Add m-esr52 at 52.6.0

57 files changed, 7810 insertions, 0 deletions

diff --git a/dom/filesystem/Directory.cpp b/dom/filesystem/Directory.cpp
new file mode 100644
index 000000000..59c78fb2c
--- /dev/null
+++ b/dom/filesystem/Directory.cpp
@@ -0,0 +1,257 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/Directory.h"
+
+#include "GetDirectoryListingTask.h"
+#include "GetFilesTask.h"
+#include "WorkerPrivate.h"
+
+#include "nsCharSeparatedTokenizer.h"
+#include "nsString.h"
+#include "mozilla/dom/DirectoryBinding.h"
+#include "mozilla/dom/FileSystemBase.h"
+#include "mozilla/dom/FileSystemUtils.h"
+#include "mozilla/dom/OSFileSystem.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(Directory)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(Directory)
+  if (tmp->mFileSystem) {
+    tmp->mFileSystem->Unlink();
+    tmp->mFileSystem = nullptr;
+  }
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mParent)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(Directory)
+  if (tmp->mFileSystem) {
+    tmp->mFileSystem->Traverse(cb);
+  }
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParent)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_WRAPPERCACHE(Directory)
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(Directory)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(Directory)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(Directory)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+/* static */ bool
+Directory::WebkitBlinkDirectoryPickerEnabled(JSContext* aCx, JSObject* aObj)
+{
+  if (NS_IsMainThread()) {
+    return Preferences::GetBool("dom.webkitBlink.dirPicker.enabled", false);
+  }
+
+  // aCx can be null when this function is called by something else than WebIDL
+  // binding code.
+  workers::WorkerPrivate* workerPrivate =
+    workers::GetCurrentThreadWorkerPrivate();
+  if (!workerPrivate) {
+    return false;
+  }
+
+  return workerPrivate->WebkitBlinkDirectoryPickerEnabled();
+}
+
+/* static */ already_AddRefed<Directory>
+Directory::Constructor(const GlobalObject& aGlobal,
+                       const nsAString& aRealPath,
+                       ErrorResult& aRv)
+{
+  nsCOMPtr<nsIFile> path;
+  aRv = NS_NewLocalFile(aRealPath, true, getter_AddRefs(path));
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  return Create(aGlobal.GetAsSupports(), path);
+}
+
+/* static */ already_AddRefed<Directory>
+Directory::Create(nsISupports* aParent, nsIFile* aFile,
+                  FileSystemBase* aFileSystem)
+{
+  MOZ_ASSERT(aParent);
+  MOZ_ASSERT(aFile);
+
+#ifdef DEBUG
+  bool isDir;
+  nsresult rv = aFile->IsDirectory(&isDir);
+  MOZ_ASSERT(NS_SUCCEEDED(rv) && isDir);
+#endif
+
+  RefPtr<Directory> directory = new Directory(aParent, aFile, aFileSystem);
+  return directory.forget();
+}
+
+Directory::Directory(nsISupports* aParent,
+                     nsIFile* aFile,
+                     FileSystemBase* aFileSystem)
+  : mParent(aParent)
+  , mFile(aFile)
+{
+  MOZ_ASSERT(aFile);
+
+  // aFileSystem can be null. In this case we create a OSFileSystem when needed.
+  if (aFileSystem) {
+    // More likely, this is a OSFileSystem. This object keeps a reference of
+    // mParent but it's not cycle collectable and to avoid manual
+    // addref/release, it's better to have 1 object per directory. For this
+    // reason we clone it here.
+    mFileSystem = aFileSystem->Clone();
+  }
+}
+
+Directory::~Directory()
+{
+}
+
+nsISupports*
+Directory::GetParentObject() const
+{
+  return mParent;
+}
+
+JSObject*
+Directory::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return DirectoryBinding::Wrap(aCx, this, aGivenProto);
+}
+
+void
+Directory::GetName(nsAString& aRetval, ErrorResult& aRv)
+{
+  aRetval.Truncate();
+
+  RefPtr<FileSystemBase> fs = GetFileSystem(aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return;
+  }
+
+  fs->GetDirectoryName(mFile, aRetval, aRv);
+}
+
+void
+Directory::GetPath(nsAString& aRetval, ErrorResult& aRv)
+{
+  // This operation is expensive. Better to cache the result.
+  if (mPath.IsEmpty()) {
+    RefPtr<FileSystemBase> fs = GetFileSystem(aRv);
+    if (NS_WARN_IF(aRv.Failed())) {
+      return;
+    }
+
+    fs->GetDOMPath(mFile, mPath, aRv);
+    if (NS_WARN_IF(aRv.Failed())) {
+      return;
+    }
+  }
+
+  aRetval = mPath;
+}
+
+nsresult
+Directory::GetFullRealPath(nsAString& aPath)
+{
+  nsresult rv = mFile->GetPath(aPath);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+already_AddRefed<Promise>
+Directory::GetFilesAndDirectories(ErrorResult& aRv)
+{
+  RefPtr<FileSystemBase> fs = GetFileSystem(aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  RefPtr<GetDirectoryListingTaskChild> task =
+    GetDirectoryListingTaskChild::Create(fs, this, mFile, mFilters, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  task->Start();
+
+  return task->GetPromise();
+}
+
+already_AddRefed<Promise>
+Directory::GetFiles(bool aRecursiveFlag, ErrorResult& aRv)
+{
+  ErrorResult rv;
+  RefPtr<FileSystemBase> fs = GetFileSystem(rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return nullptr;
+  }
+
+  RefPtr<GetFilesTaskChild> task =
+    GetFilesTaskChild::Create(fs, this, mFile, aRecursiveFlag, rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return nullptr;
+  }
+
+  task->Start();
+
+  return task->GetPromise();
+}
+
+void
+Directory::SetContentFilters(const nsAString& aFilters)
+{
+  mFilters = aFilters;
+}
+
+FileSystemBase*
+Directory::GetFileSystem(ErrorResult& aRv)
+{
+  if (!mFileSystem) {
+    nsAutoString path;
+    aRv = mFile->GetPath(path);
+    if (NS_WARN_IF(aRv.Failed())) {
+      return nullptr;
+    }
+
+    RefPtr<OSFileSystem> fs = new OSFileSystem(path);
+    fs->Init(mParent);
+
+    mFileSystem = fs;
+  }
+
+  return mFileSystem;
+}
+
+
+bool
+Directory::ClonableToDifferentThreadOrProcess() const
+{
+  // If we don't have a fileSystem we are going to create a OSFileSystem that is
+  // clonable everywhere.
+  if (!mFileSystem) {
+    return true;
+  }
+
+  return mFileSystem->ClonableToDifferentThreadOrProcess();
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/filesystem/Directory.h b/dom/filesystem/Directory.h
new file mode 100644
index 000000000..3a532e043
--- /dev/null
+++ b/dom/filesystem/Directory.h
@@ -0,0 +1,131 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_Directory_h
+#define mozilla_dom_Directory_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/ErrorResult.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/File.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsWrapperCache.h"
+
+namespace mozilla {
+namespace dom {
+
+class FileSystemBase;
+class Promise;
+class StringOrFileOrDirectory;
+
+class Directory final
+  : public nsISupports
+  , public nsWrapperCache
+{
+public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(Directory)
+
+  static bool
+  WebkitBlinkDirectoryPickerEnabled(JSContext* aCx, JSObject* aObj);
+
+  static already_AddRefed<Directory>
+  Constructor(const GlobalObject& aGlobal,
+              const nsAString& aRealPath,
+              ErrorResult& aRv);
+
+  static already_AddRefed<Directory>
+  Create(nsISupports* aParent, nsIFile* aDirectory,
+         FileSystemBase* aFileSystem = 0);
+
+  // ========= Begin WebIDL bindings. ===========
+
+  nsISupports*
+  GetParentObject() const;
+
+  virtual JSObject*
+  WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  void
+  GetName(nsAString& aRetval, ErrorResult& aRv);
+
+  // From https://microsoftedge.github.io/directory-upload/proposal.html#directory-interface :
+
+  void
+  GetPath(nsAString& aRetval, ErrorResult& aRv);
+
+  nsresult
+  GetFullRealPath(nsAString& aPath);
+
+  already_AddRefed<Promise>
+  GetFilesAndDirectories(ErrorResult& aRv);
+
+  already_AddRefed<Promise>
+  GetFiles(bool aRecursiveFlag, ErrorResult& aRv);
+
+  // =========== End WebIDL bindings.============
+
+  /**
+   * Sets a semi-colon separated list of filters to filter-in or filter-out
+   * certain types of files when the contents of this directory are requested
+   * via a GetFilesAndDirectories() call.
+   *
+   * Currently supported keywords:
+   *
+   *   * filter-out-sensitive
+   *       This keyword filters out files or directories that we don't wish to
+   *       make available to Web content because we are concerned that there is
+   *       a risk that users may unwittingly give Web content access to them
+   *       and suffer undesirable consequences.  The details of what is
+   *       filtered out can be found in GetDirectoryListingTask::Work.
+   *
+   * In future, we will likely support filtering based on filename extensions
+   * (for example, aFilters could be "*.jpg; *.jpeg; *.gif"), but that isn't
+   * supported yet.  Once supported, files that don't match a specified
+   * extension (if any are specified) would be filtered out.  This
+   * functionality would allow us to apply the 'accept' attribute from
+   * <input type=file directory accept="..."> to the results of a directory
+   * picker operation.
+   */
+  void
+  SetContentFilters(const nsAString& aFilters);
+
+  FileSystemBase*
+  GetFileSystem(ErrorResult& aRv);
+
+  bool
+  ClonableToDifferentThreadOrProcess() const;
+
+  nsIFile*
+  GetInternalNsIFile() const
+  {
+    return mFile;
+  }
+
+private:
+  Directory(nsISupports* aParent,
+            nsIFile* aFile,
+            FileSystemBase* aFileSystem = nullptr);
+  ~Directory();
+
+  /*
+   * Convert relative DOM path to the absolute real path.
+   */
+  nsresult
+  DOMPathToRealPath(const nsAString& aPath, nsIFile** aFile) const;
+
+  nsCOMPtr<nsISupports> mParent;
+  RefPtr<FileSystemBase> mFileSystem;
+  nsCOMPtr<nsIFile> mFile;
+
+  nsString mFilters;
+  nsString mPath;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_Directory_h
diff --git a/dom/filesystem/FileSystemBase.cpp b/dom/filesystem/FileSystemBase.cpp
new file mode 100644
index 000000000..f44f4fbf1
--- /dev/null
+++ b/dom/filesystem/FileSystemBase.cpp
@@ -0,0 +1,169 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/FileSystemBase.h"
+
+#include "nsCharSeparatedTokenizer.h"
+#include "OSFileSystem.h"
+
+namespace mozilla {
+namespace dom {
+
+FileSystemBase::FileSystemBase()
+  : mShutdown(false)
+#ifdef DEBUG
+  , mOwningThread(PR_GetCurrentThread())
+#endif
+{
+}
+
+FileSystemBase::~FileSystemBase()
+{
+  AssertIsOnOwningThread();
+}
+
+void
+FileSystemBase::Shutdown()
+{
+  AssertIsOnOwningThread();
+  mShutdown = true;
+}
+
+nsISupports*
+FileSystemBase::GetParentObject() const
+{
+  AssertIsOnOwningThread();
+  return nullptr;
+}
+
+bool
+FileSystemBase::GetRealPath(BlobImpl* aFile, nsIFile** aPath) const
+{
+  AssertIsOnOwningThread();
+  MOZ_ASSERT(aFile, "aFile Should not be null.");
+  MOZ_ASSERT(aPath);
+
+  nsAutoString filePath;
+  ErrorResult rv;
+  aFile->GetMozFullPathInternal(filePath, rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    rv.SuppressException();
+    return false;
+  }
+
+  rv = NS_NewLocalFile(filePath, true, aPath);
+  if (NS_WARN_IF(rv.Failed())) {
+    rv.SuppressException();
+    return false;
+  }
+
+  return true;
+}
+
+bool
+FileSystemBase::IsSafeFile(nsIFile* aFile) const
+{
+  AssertIsOnOwningThread();
+  return false;
+}
+
+bool
+FileSystemBase::IsSafeDirectory(Directory* aDir) const
+{
+  AssertIsOnOwningThread();
+  return false;
+}
+
+void
+FileSystemBase::GetDirectoryName(nsIFile* aFile, nsAString& aRetval,
+                                 ErrorResult& aRv) const
+{
+  AssertIsOnOwningThread();
+  MOZ_ASSERT(aFile);
+
+  aRv = aFile->GetLeafName(aRetval);
+  NS_WARNING_ASSERTION(!aRv.Failed(), "GetLeafName failed");
+}
+
+void
+FileSystemBase::GetDOMPath(nsIFile* aFile,
+                           nsAString& aRetval,
+                           ErrorResult& aRv) const
+{
+  AssertIsOnOwningThread();
+  MOZ_ASSERT(aFile);
+
+  aRetval.Truncate();
+
+  nsCOMPtr<nsIFile> fileSystemPath;
+  aRv = NS_NewLocalFile(LocalRootPath(), true, getter_AddRefs(fileSystemPath));
+  if (NS_WARN_IF(aRv.Failed())) {
+    return;
+  }
+
+  nsCOMPtr<nsIFile> path;
+  aRv = aFile->Clone(getter_AddRefs(path));
+  if (NS_WARN_IF(aRv.Failed())) {
+    return;
+  }
+
+  nsTArray<nsString> parts;
+
+  while (true) {
+    nsAutoString leafName;
+    aRv = path->GetLeafName(leafName);
+    if (NS_WARN_IF(aRv.Failed())) {
+      return;
+    }
+
+    if (!leafName.IsEmpty()) {
+      parts.AppendElement(leafName);
+    }
+
+    bool equal = false;
+    aRv = fileSystemPath->Equals(path, &equal);
+    if (NS_WARN_IF(aRv.Failed())) {
+      return;
+    }
+
+    if (equal) {
+      break;
+    }
+
+    nsCOMPtr<nsIFile> parentPath;
+    aRv = path->GetParent(getter_AddRefs(parentPath));
+    if (NS_WARN_IF(aRv.Failed())) {
+      return;
+    }
+
+    MOZ_ASSERT(parentPath);
+
+    aRv = parentPath->Clone(getter_AddRefs(path));
+    if (NS_WARN_IF(aRv.Failed())) {
+      return;
+    }
+  }
+
+  if (parts.IsEmpty()) {
+    aRetval.AppendLiteral(FILESYSTEM_DOM_PATH_SEPARATOR_LITERAL);
+    return;
+  }
+
+  for (int32_t i = parts.Length() - 1; i >= 0; --i) {
+    aRetval.AppendLiteral(FILESYSTEM_DOM_PATH_SEPARATOR_LITERAL);
+    aRetval.Append(parts[i]);
+  }
+}
+
+void
+FileSystemBase::AssertIsOnOwningThread() const
+{
+  MOZ_ASSERT(mOwningThread);
+  MOZ_ASSERT(PR_GetCurrentThread() == mOwningThread);
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/filesystem/FileSystemBase.h b/dom/filesystem/FileSystemBase.h
new file mode 100644
index 000000000..0b875eb14
--- /dev/null
+++ b/dom/filesystem/FileSystemBase.h
@@ -0,0 +1,118 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystemBase_h
+#define mozilla_dom_FileSystemBase_h
+
+#include "nsString.h"
+#include "Directory.h"
+
+namespace mozilla {
+namespace dom {
+
+class BlobImpl;
+
+class FileSystemBase
+{
+public:
+  NS_INLINE_DECL_REFCOUNTING(FileSystemBase)
+
+  FileSystemBase();
+
+  virtual void
+  Shutdown();
+
+  // SerializeDOMPath the FileSystem to string.
+  virtual void
+  SerializeDOMPath(nsAString& aOutput) const = 0;
+
+  virtual already_AddRefed<FileSystemBase>
+  Clone() = 0;
+
+  virtual bool
+  ShouldCreateDirectory() = 0;
+
+  virtual nsISupports*
+  GetParentObject() const;
+
+  virtual void
+  GetDirectoryName(nsIFile* aFile, nsAString& aRetval,
+                   ErrorResult& aRv) const;
+
+  void
+  GetDOMPath(nsIFile* aFile, nsAString& aRetval, ErrorResult& aRv) const;
+
+  /*
+   * Return the local root path of the FileSystem implementation.
+   * For OSFileSystem, this is equal to the path of the root Directory;
+   * For DeviceStorageFileSystem, this is the path of the SDCard, parent
+   * directory of the exposed root Directory (per type).
+   */
+  const nsAString&
+  LocalRootPath() const
+  {
+    return mLocalRootPath;
+  }
+
+  bool
+  IsShutdown() const
+  {
+    return mShutdown;
+  }
+
+  virtual bool
+  IsSafeFile(nsIFile* aFile) const;
+
+  virtual bool
+  IsSafeDirectory(Directory* aDir) const;
+
+  bool
+  GetRealPath(BlobImpl* aFile, nsIFile** aPath) const;
+
+  // IPC initialization
+  // See how these 2 methods are used in FileSystemTaskChildBase.
+
+  virtual bool
+  NeedToGoToMainThread() const { return false; }
+
+  virtual nsresult
+  MainThreadWork() { return NS_ERROR_FAILURE; }
+
+  virtual bool
+  ClonableToDifferentThreadOrProcess() const { return false; }
+
+  // CC methods
+  virtual void Unlink() {}
+  virtual void Traverse(nsCycleCollectionTraversalCallback &cb) {}
+
+  void
+  AssertIsOnOwningThread() const;
+
+protected:
+  virtual ~FileSystemBase();
+
+  // The local path of the root (i.e. the OS path, with OS path separators, of
+  // the OS directory that acts as the root of this OSFileSystem).
+  // This path must be set by the FileSystem implementation immediately
+  // because it will be used for the validation of any FileSystemTaskChildBase.
+  // The concept of this path is that, any task will never go out of it and this
+  // must be considered the OS 'root' of the current FileSystem. Different
+  // Directory object can have different OS 'root' path.
+  // To be more clear, any path managed by this FileSystem implementation must
+  // be discendant of this local root path.
+  nsString mLocalRootPath;
+
+  bool mShutdown;
+
+#ifdef DEBUG
+  PRThread* mOwningThread;
+#endif
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileSystemBase_h
diff --git a/dom/filesystem/FileSystemRequestParent.cpp b/dom/filesystem/FileSystemRequestParent.cpp
new file mode 100644
index 000000000..0b9d6c18a
--- /dev/null
+++ b/dom/filesystem/FileSystemRequestParent.cpp
@@ -0,0 +1,194 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/FileSystemRequestParent.h"
+#include "mozilla/dom/PFileSystemParams.h"
+
+#include "GetDirectoryListingTask.h"
+#include "GetFileOrDirectoryTask.h"
+
+#include "mozilla/AppProcessChecker.h"
+#include "mozilla/dom/ContentParent.h"
+#include "mozilla/dom/FileSystemBase.h"
+#include "mozilla/dom/FileSystemSecurity.h"
+#include "mozilla/ipc/BackgroundParent.h"
+#include "mozilla/Unused.h"
+#include "nsProxyRelease.h"
+
+using namespace mozilla::ipc;
+
+namespace mozilla {
+namespace dom {
+
+FileSystemRequestParent::FileSystemRequestParent()
+  : mDestroyed(false)
+{
+  AssertIsOnBackgroundThread();
+}
+
+FileSystemRequestParent::~FileSystemRequestParent()
+{
+  AssertIsOnBackgroundThread();
+}
+
+#define FILESYSTEM_REQUEST_PARENT_DISPATCH_ENTRY(name)                         \
+    case FileSystemParams::TFileSystem##name##Params: {                        \
+      const FileSystem##name##Params& p = aParams;                             \
+      mFileSystem = new OSFileSystemParent(p.filesystem());                    \
+      MOZ_ASSERT(mFileSystem);                                                 \
+      mTask = name##TaskParent::Create(mFileSystem, p, this, rv);              \
+      if (NS_WARN_IF(rv.Failed())) {                                           \
+        rv.SuppressException();                                                \
+        return false;                                                          \
+      }                                                                        \
+      break;                                                                   \
+    }
+
+bool
+FileSystemRequestParent::Initialize(const FileSystemParams& aParams)
+{
+  AssertIsOnBackgroundThread();
+
+  ErrorResult rv;
+
+  switch (aParams.type()) {
+
+    FILESYSTEM_REQUEST_PARENT_DISPATCH_ENTRY(GetDirectoryListing)
+    FILESYSTEM_REQUEST_PARENT_DISPATCH_ENTRY(GetFileOrDirectory)
+    FILESYSTEM_REQUEST_PARENT_DISPATCH_ENTRY(GetFiles)
+
+    default: {
+      NS_RUNTIMEABORT("not reached");
+      break;
+    }
+  }
+
+  if (NS_WARN_IF(!mTask || !mFileSystem)) {
+    // Should never reach here.
+    return false;
+  }
+
+  return true;
+}
+
+namespace {
+
+class CheckPermissionRunnable final : public Runnable
+{
+public:
+  CheckPermissionRunnable(already_AddRefed<ContentParent> aParent,
+                          FileSystemRequestParent* aActor,
+                          FileSystemTaskParentBase* aTask,
+                          const nsAString& aPath)
+    : mContentParent(aParent)
+    , mActor(aActor)
+    , mTask(aTask)
+    , mPath(aPath)
+    , mBackgroundEventTarget(NS_GetCurrentThread())
+  {
+    AssertIsInMainProcess();
+    AssertIsOnBackgroundThread();
+
+    MOZ_ASSERT(mContentParent);
+    MOZ_ASSERT(mActor);
+    MOZ_ASSERT(mTask);
+    MOZ_ASSERT(mBackgroundEventTarget);
+  }
+
+  NS_IMETHOD
+  Run() override
+  {
+    if (NS_IsMainThread()) {
+      auto raii = mozilla::MakeScopeExit([&] { mContentParent = nullptr; });
+
+
+      if (!mozilla::Preferences::GetBool("dom.filesystem.pathcheck.disabled", false)) {
+        RefPtr<FileSystemSecurity> fss = FileSystemSecurity::Get();
+        if (NS_WARN_IF(!fss ||
+                       !fss->ContentProcessHasAccessTo(mContentParent->ChildID(),
+                                                       mPath))) {
+          mContentParent->KillHard("This path is not allowed.");
+          return NS_OK;
+        }
+      }
+
+      return mBackgroundEventTarget->Dispatch(this, NS_DISPATCH_NORMAL);
+    }
+
+    AssertIsOnBackgroundThread();
+
+    // It can happen that this actor has been destroyed in the meantime we were
+    // on the main-thread.
+    if (!mActor->Destroyed()) {
+      mTask->Start();
+    }
+
+    return NS_OK;
+  }
+
+private:
+  ~CheckPermissionRunnable()
+  {
+     NS_ProxyRelease(mBackgroundEventTarget, mActor.forget());
+  }
+
+  RefPtr<ContentParent> mContentParent;
+  RefPtr<FileSystemRequestParent> mActor;
+  RefPtr<FileSystemTaskParentBase> mTask;
+  const nsString mPath;
+
+  nsCOMPtr<nsIEventTarget> mBackgroundEventTarget;
+};
+
+} // anonymous
+
+void
+FileSystemRequestParent::Start()
+{
+  AssertIsInMainProcess();
+  AssertIsOnBackgroundThread();
+
+  MOZ_ASSERT(!mDestroyed);
+  MOZ_ASSERT(mFileSystem);
+  MOZ_ASSERT(mTask);
+
+  nsAutoString path;
+  if (NS_WARN_IF(NS_FAILED(mTask->GetTargetPath(path)))) {
+    Unused << Send__delete__(this, FileSystemErrorResponse(NS_ERROR_DOM_SECURITY_ERR));
+    return;
+  }
+
+  RefPtr<ContentParent> parent = BackgroundParent::GetContentParent(Manager());
+
+  // If the ContentParent is null we are dealing with a same-process actor.
+  if (!parent) {
+    mTask->Start();
+    return;
+  }
+
+  RefPtr<Runnable> runnable =
+    new CheckPermissionRunnable(parent.forget(), this, mTask, path);
+  NS_DispatchToMainThread(runnable);
+}
+
+void
+FileSystemRequestParent::ActorDestroy(ActorDestroyReason aWhy)
+{
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(!mDestroyed);
+
+  if (!mFileSystem) {
+    return;
+  }
+
+  mFileSystem->Shutdown();
+  mFileSystem = nullptr;
+  mTask = nullptr;
+  mDestroyed = true;
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/filesystem/FileSystemRequestParent.h b/dom/filesystem/FileSystemRequestParent.h
new file mode 100644
index 000000000..a5f4cd6cc
--- /dev/null
+++ b/dom/filesystem/FileSystemRequestParent.h
@@ -0,0 +1,52 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystemRequestParent_h
+#define mozilla_dom_FileSystemRequestParent_h
+
+#include "mozilla/dom/PFileSystemRequestParent.h"
+#include "mozilla/dom/FileSystemBase.h"
+
+namespace mozilla {
+namespace dom {
+
+class FileSystemParams;
+class FileSystemTaskParentBase;
+
+class FileSystemRequestParent final : public PFileSystemRequestParent
+{
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(FileSystemRequestParent)
+
+public:
+  FileSystemRequestParent();
+
+  bool
+  Initialize(const FileSystemParams& aParams);
+
+  void
+  Start();
+
+  bool Destroyed() const
+  {
+    return mDestroyed;
+  }
+
+  virtual void
+  ActorDestroy(ActorDestroyReason why) override;
+
+private:
+  ~FileSystemRequestParent();
+
+  RefPtr<FileSystemBase> mFileSystem;
+  RefPtr<FileSystemTaskParentBase> mTask;
+
+  bool mDestroyed;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileSystemRequestParent_h
diff --git a/dom/filesystem/FileSystemSecurity.cpp b/dom/filesystem/FileSystemSecurity.cpp
new file mode 100644
index 000000000..b3d425817
--- /dev/null
+++ b/dom/filesystem/FileSystemSecurity.cpp
@@ -0,0 +1,119 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FileSystemSecurity.h"
+#include "FileSystemUtils.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/StaticPtr.h"
+
+namespace mozilla {
+namespace dom {
+
+namespace {
+
+StaticRefPtr<FileSystemSecurity> gFileSystemSecurity;
+
+} // anonymous
+
+/* static */ already_AddRefed<FileSystemSecurity>
+FileSystemSecurity::Get()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  AssertIsInMainProcess();
+
+  RefPtr<FileSystemSecurity> service = gFileSystemSecurity.get();
+  return service.forget();
+}
+
+/* static */ already_AddRefed<FileSystemSecurity>
+FileSystemSecurity::GetOrCreate()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  AssertIsInMainProcess();
+
+  if (!gFileSystemSecurity) {
+    gFileSystemSecurity = new FileSystemSecurity();
+    ClearOnShutdown(&gFileSystemSecurity);
+  }
+
+  RefPtr<FileSystemSecurity> service = gFileSystemSecurity.get();
+  return service.forget();
+}
+
+FileSystemSecurity::FileSystemSecurity()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  AssertIsInMainProcess();
+}
+
+FileSystemSecurity::~FileSystemSecurity()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  AssertIsInMainProcess();
+}
+
+void
+FileSystemSecurity::GrantAccessToContentProcess(ContentParentId aId,
+                                                const nsAString& aDirectoryPath)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  AssertIsInMainProcess();
+
+  nsTArray<nsString>* paths;
+  if (!mPaths.Get(aId, &paths)) {
+    paths = new nsTArray<nsString>();
+    mPaths.Put(aId, paths);
+  } else if (paths->Contains(aDirectoryPath)) {
+    return;
+  }
+
+  paths->AppendElement(aDirectoryPath);
+}
+
+void
+FileSystemSecurity::Forget(ContentParentId aId)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  AssertIsInMainProcess();
+
+  mPaths.Remove(aId);
+}
+
+bool
+FileSystemSecurity::ContentProcessHasAccessTo(ContentParentId aId,
+                                              const nsAString& aPath)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  AssertIsInMainProcess();
+
+#if defined(XP_WIN)
+  if (StringBeginsWith(aPath, NS_LITERAL_STRING("..\\")) ||
+      FindInReadable(NS_LITERAL_STRING("\\..\\"), aPath)) {
+    return false;
+  }
+#elif defined(XP_UNIX)
+  if (StringBeginsWith(aPath, NS_LITERAL_STRING("../")) ||
+      FindInReadable(NS_LITERAL_STRING("/../"), aPath)) {
+    return false;
+  }
+#endif
+
+  nsTArray<nsString>* paths;
+  if (!mPaths.Get(aId, &paths)) {
+    return false;
+  }
+
+  for (uint32_t i = 0, len = paths->Length(); i < len; ++i) {
+    if (FileSystemUtils::IsDescendantPath(paths->ElementAt(i), aPath)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+} // dom namespace
+} // mozilla namespace
diff --git a/dom/filesystem/FileSystemSecurity.h b/dom/filesystem/FileSystemSecurity.h
new file mode 100644
index 000000000..fe61dc7c6
--- /dev/null
+++ b/dom/filesystem/FileSystemSecurity.h
@@ -0,0 +1,48 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystemSecurity_h
+#define mozilla_dom_FileSystemSecurity_h
+
+#include "mozilla/dom/ipc/IdType.h"
+#include "nsClassHashtable.h"
+#include "nsISupportsImpl.h"
+
+namespace mozilla {
+namespace dom {
+
+class FileSystemSecurity final
+{
+public:
+  NS_INLINE_DECL_REFCOUNTING(FileSystemSecurity)
+
+  static already_AddRefed<FileSystemSecurity>
+  Get();
+
+  static already_AddRefed<FileSystemSecurity>
+  GetOrCreate();
+
+  void
+  GrantAccessToContentProcess(ContentParentId aId,
+                              const nsAString& aDirectoryPath);
+
+  void
+  Forget(ContentParentId aId);
+
+  bool
+  ContentProcessHasAccessTo(ContentParentId aId, const nsAString& aPath);
+
+private:
+  FileSystemSecurity();
+  ~FileSystemSecurity();
+
+  nsClassHashtable<nsUint64HashKey, nsTArray<nsString>> mPaths;
+};
+
+} // dom namespace
+} // mozilla namespace
+
+#endif // mozilla_dom_FileSystemSecurity_h
diff --git a/dom/filesystem/FileSystemTaskBase.cpp b/dom/filesystem/FileSystemTaskBase.cpp
new file mode 100644
index 000000000..481002b7d
--- /dev/null
+++ b/dom/filesystem/FileSystemTaskBase.cpp
@@ -0,0 +1,379 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/FileSystemTaskBase.h"
+
+#include "nsNetCID.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/dom/FileSystemBase.h"
+#include "mozilla/dom/FileSystemRequestParent.h"
+#include "mozilla/dom/FileSystemUtils.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/ipc/BlobParent.h"
+#include "mozilla/ipc/BackgroundChild.h"
+#include "mozilla/ipc/BackgroundParent.h"
+#include "mozilla/ipc/PBackgroundChild.h"
+#include "mozilla/Unused.h"
+#include "nsProxyRelease.h"
+
+namespace mozilla {
+namespace dom {
+
+namespace {
+
+nsresult
+FileSystemErrorFromNsError(const nsresult& aErrorValue)
+{
+  uint16_t module = NS_ERROR_GET_MODULE(aErrorValue);
+  if (module == NS_ERROR_MODULE_DOM_FILESYSTEM ||
+      module == NS_ERROR_MODULE_DOM_FILE ||
+      module == NS_ERROR_MODULE_DOM) {
+    return aErrorValue;
+  }
+
+  switch (aErrorValue) {
+    case NS_OK:
+      return NS_OK;
+
+    case NS_ERROR_FILE_INVALID_PATH:
+    case NS_ERROR_FILE_UNRECOGNIZED_PATH:
+      return NS_ERROR_DOM_FILESYSTEM_INVALID_PATH_ERR;
+
+    case NS_ERROR_FILE_DESTINATION_NOT_DIR:
+      return NS_ERROR_DOM_FILESYSTEM_INVALID_MODIFICATION_ERR;
+
+    case NS_ERROR_FILE_ACCESS_DENIED:
+    case NS_ERROR_FILE_DIR_NOT_EMPTY:
+      return NS_ERROR_DOM_FILESYSTEM_NO_MODIFICATION_ALLOWED_ERR;
+
+    case NS_ERROR_FILE_TARGET_DOES_NOT_EXIST:
+    case NS_ERROR_NOT_AVAILABLE:
+      return NS_ERROR_DOM_FILE_NOT_FOUND_ERR;
+
+    case NS_ERROR_FILE_ALREADY_EXISTS:
+      return NS_ERROR_DOM_FILESYSTEM_PATH_EXISTS_ERR;
+
+    case NS_ERROR_FILE_NOT_DIRECTORY:
+      return NS_ERROR_DOM_FILESYSTEM_TYPE_MISMATCH_ERR;
+
+    case NS_ERROR_UNEXPECTED:
+    default:
+      return NS_ERROR_DOM_FILESYSTEM_UNKNOWN_ERR;
+  }
+}
+
+nsresult
+DispatchToIOThread(nsIRunnable* aRunnable)
+{
+  MOZ_ASSERT(aRunnable);
+
+  nsCOMPtr<nsIEventTarget> target
+    = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
+  MOZ_ASSERT(target);
+
+  return target->Dispatch(aRunnable, NS_DISPATCH_NORMAL);
+}
+
+// This runnable is used when an error value is set before doing any real
+// operation on the I/O thread. In this case we skip all and we directly
+// communicate the error.
+class ErrorRunnable final : public CancelableRunnable
+{
+public:
+  explicit ErrorRunnable(FileSystemTaskChildBase* aTask)
+    : mTask(aTask)
+  {
+    MOZ_ASSERT(aTask);
+  }
+
+  NS_IMETHOD
+  Run() override
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    MOZ_ASSERT(mTask->HasError());
+
+    mTask->HandlerCallback();
+    return NS_OK;
+  }
+
+private:
+  RefPtr<FileSystemTaskChildBase> mTask;
+};
+
+} // anonymous namespace
+
+NS_IMPL_ISUPPORTS(FileSystemTaskChildBase, nsIIPCBackgroundChildCreateCallback)
+
+/**
+ * FileSystemTaskBase class
+ */
+
+FileSystemTaskChildBase::FileSystemTaskChildBase(FileSystemBase* aFileSystem)
+  : mErrorValue(NS_OK)
+  , mFileSystem(aFileSystem)
+{
+  MOZ_ASSERT(aFileSystem, "aFileSystem should not be null.");
+  aFileSystem->AssertIsOnOwningThread();
+}
+
+FileSystemTaskChildBase::~FileSystemTaskChildBase()
+{
+  mFileSystem->AssertIsOnOwningThread();
+}
+
+FileSystemBase*
+FileSystemTaskChildBase::GetFileSystem() const
+{
+  mFileSystem->AssertIsOnOwningThread();
+  return mFileSystem.get();
+}
+
+void
+FileSystemTaskChildBase::Start()
+{
+  mFileSystem->AssertIsOnOwningThread();
+
+  mozilla::ipc::PBackgroundChild* actor =
+    mozilla::ipc::BackgroundChild::GetForCurrentThread();
+  if (actor) {
+    ActorCreated(actor);
+  } else {
+    if (NS_WARN_IF(
+        !mozilla::ipc::BackgroundChild::GetOrCreateForCurrentThread(this))) {
+      MOZ_CRASH();
+    }
+  }
+}
+
+void
+FileSystemTaskChildBase::ActorFailed()
+{
+  MOZ_CRASH("Failed to create a PBackgroundChild actor!");
+}
+
+void
+FileSystemTaskChildBase::ActorCreated(mozilla::ipc::PBackgroundChild* aActor)
+{
+  if (HasError()) {
+    // In this case we don't want to use IPC at all.
+    RefPtr<ErrorRunnable> runnable = new ErrorRunnable(this);
+    DebugOnly<nsresult> rv = NS_DispatchToCurrentThread(runnable);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_DispatchToCurrentThread failed");
+    return;
+  }
+
+  if (mFileSystem->IsShutdown()) {
+    return;
+  }
+
+  nsAutoString serialization;
+  mFileSystem->SerializeDOMPath(serialization);
+
+  ErrorResult rv;
+  FileSystemParams params = GetRequestParams(serialization, rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    rv.SuppressException();
+    return;
+  }
+
+  // Retain a reference so the task object isn't deleted without IPDL's
+  // knowledge. The reference will be released by
+  // mozilla::ipc::BackgroundChildImpl::DeallocPFileSystemRequestChild.
+  NS_ADDREF_THIS();
+
+  mozilla::ipc::PBackgroundChild* actor =
+    mozilla::ipc::BackgroundChild::GetForCurrentThread();
+  MOZ_ASSERT(actor);
+
+  actor->SendPFileSystemRequestConstructor(this, params);
+}
+
+void
+FileSystemTaskChildBase::SetRequestResult(const FileSystemResponseValue& aValue)
+{
+  mFileSystem->AssertIsOnOwningThread();
+
+  if (aValue.type() == FileSystemResponseValue::TFileSystemErrorResponse) {
+    FileSystemErrorResponse r = aValue;
+    mErrorValue = r.error();
+  } else {
+    ErrorResult rv;
+    SetSuccessRequestResult(aValue, rv);
+    mErrorValue = rv.StealNSResult();
+  }
+}
+
+bool
+FileSystemTaskChildBase::Recv__delete__(const FileSystemResponseValue& aValue)
+{
+  mFileSystem->AssertIsOnOwningThread();
+
+  SetRequestResult(aValue);
+  HandlerCallback();
+  return true;
+}
+
+void
+FileSystemTaskChildBase::SetError(const nsresult& aErrorValue)
+{
+  mErrorValue = FileSystemErrorFromNsError(aErrorValue);
+}
+
+/**
+ * FileSystemTaskParentBase class
+ */
+
+FileSystemTaskParentBase::FileSystemTaskParentBase(FileSystemBase* aFileSystem,
+                                                   const FileSystemParams& aParam,
+                                                   FileSystemRequestParent* aParent)
+  : mErrorValue(NS_OK)
+  , mFileSystem(aFileSystem)
+  , mRequestParent(aParent)
+  , mBackgroundEventTarget(NS_GetCurrentThread())
+{
+  MOZ_ASSERT(XRE_IsParentProcess(),
+             "Only call from parent process!");
+  MOZ_ASSERT(aFileSystem, "aFileSystem should not be null.");
+  MOZ_ASSERT(aParent);
+  MOZ_ASSERT(mBackgroundEventTarget);
+  AssertIsOnBackgroundThread();
+}
+
+FileSystemTaskParentBase::~FileSystemTaskParentBase()
+{
+  // This task can be released on different threads because we dispatch it (as
+  // runnable) to main-thread, I/O and then back to the PBackground thread.
+  NS_ProxyRelease(mBackgroundEventTarget, mFileSystem.forget());
+  NS_ProxyRelease(mBackgroundEventTarget, mRequestParent.forget());
+}
+
+void
+FileSystemTaskParentBase::Start()
+{
+  AssertIsOnBackgroundThread();
+  mFileSystem->AssertIsOnOwningThread();
+
+  if (NeedToGoToMainThread()) {
+    DebugOnly<nsresult> rv = NS_DispatchToMainThread(this, NS_DISPATCH_NORMAL);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_DispatchToCurrentThread failed");
+    return;
+  }
+
+  DebugOnly<nsresult> rv = DispatchToIOThread(this);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "DispatchToIOThread failed");
+}
+
+void
+FileSystemTaskParentBase::HandleResult()
+{
+  AssertIsOnBackgroundThread();
+  mFileSystem->AssertIsOnOwningThread();
+
+  if (mFileSystem->IsShutdown()) {
+    return;
+  }
+
+  MOZ_ASSERT(mRequestParent);
+  Unused << mRequestParent->Send__delete__(mRequestParent, GetRequestResult());
+}
+
+FileSystemResponseValue
+FileSystemTaskParentBase::GetRequestResult() const
+{
+  AssertIsOnBackgroundThread();
+  mFileSystem->AssertIsOnOwningThread();
+
+  if (HasError()) {
+    return FileSystemErrorResponse(mErrorValue);
+  }
+
+  ErrorResult rv;
+  FileSystemResponseValue value = GetSuccessRequestResult(rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    return FileSystemErrorResponse(rv.StealNSResult());
+  }
+
+  return value;
+}
+
+void
+FileSystemTaskParentBase::SetError(const nsresult& aErrorValue)
+{
+  mErrorValue = FileSystemErrorFromNsError(aErrorValue);
+}
+
+bool
+FileSystemTaskParentBase::NeedToGoToMainThread() const
+{
+  return mFileSystem->NeedToGoToMainThread();
+}
+
+nsresult
+FileSystemTaskParentBase::MainThreadWork()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  return mFileSystem->MainThreadWork();
+}
+
+NS_IMETHODIMP
+FileSystemTaskParentBase::Run()
+{
+  // This method can run in 3 different threads. Here why:
+  // 1. if we are on the main-thread it's because the task must do something
+  //    here. If no errors are returned we go the step 2.
+  // 2. We can be here directly if the task doesn't have nothing to do on the
+  //    main-thread. We are are on the I/O thread and we call IOWork().
+  // 3. Both step 1 (in case of error) and step 2 end up here where return the
+  //    value back to the PBackground thread.
+  if (NS_IsMainThread()) {
+    MOZ_ASSERT(NeedToGoToMainThread());
+
+    nsresult rv = MainThreadWork();
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      SetError(rv);
+
+      // Something when wrong. Let's go to the Background thread directly
+      // skipping the I/O thread step.
+      rv = mBackgroundEventTarget->Dispatch(this, NS_DISPATCH_NORMAL);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return rv;
+      }
+    }
+
+    // Next step must happen on the I/O thread.
+    rv = DispatchToIOThread(this);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+
+    return NS_OK;
+  }
+
+  // Run I/O thread tasks
+  if (!IsOnBackgroundThread()) {
+    nsresult rv = IOWork();
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      SetError(rv);
+    }
+
+    // Let's go back to PBackground thread to finish the work.
+    rv = mBackgroundEventTarget->Dispatch(this, NS_DISPATCH_NORMAL);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+
+    return NS_OK;
+  }
+
+  // If we are here, it's because the I/O work has been done and we have to
+  // handle the result back via IPC.
+  AssertIsOnBackgroundThread();
+  HandleResult();
+  return NS_OK;
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/filesystem/FileSystemTaskBase.h b/dom/filesystem/FileSystemTaskBase.h
new file mode 100644
index 000000000..9910f4c1f
--- /dev/null
+++ b/dom/filesystem/FileSystemTaskBase.h
@@ -0,0 +1,279 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystemTaskBase_h
+#define mozilla_dom_FileSystemTaskBase_h
+
+#include "mozilla/ErrorResult.h"
+#include "mozilla/dom/FileSystemRequestParent.h"
+#include "mozilla/dom/PFileSystemRequestChild.h"
+#include "nsIIPCBackgroundChildCreateCallback.h"
+#include "nsThreadUtils.h"
+
+namespace mozilla {
+namespace dom {
+
+class BlobImpl;
+class FileSystemBase;
+class FileSystemParams;
+class PBlobParent;
+
+/*
+ * The base class to implement a Task class.
+ * The file system operations can only be performed in the parent process. In
+ * order to avoid duplicated code, we used PBackground for child-parent and
+ * parent-parent communications.
+ *
+ * The following diagram illustrates the how a API call from the content page
+ * starts a task and gets call back results.
+ *
+ * The left block is the call sequence inside any process loading content, while
+ * the right block is the call sequence only inside the parent process.
+ *
+ *       Page
+ *        |
+ *        | (1)
+ *  ______|_________________________     |    _________________________________
+ * |      |                          |   |   |                                 |
+ * |      |                          |   |   |                                 |
+ * |      V                          |  IPC  | PBackground thread on           |
+ * | [new FileSystemTaskChildBase()] |   |   | the parent process              |
+ * |         |                       |   |   |                                 |
+ * |         | (2)                   |       |                                 |
+ * |         V                       |  (3)  |                                 |
+ * |    [GetRequestParams]------------------->[new FileSystemTaskParentBase()] |
+ * |                                 |       |          |                      |
+ * |                                 |   |   |          | (4)   _____________  |
+ * |                                 |   |   |          |      |             | |
+ * |                                 |   |   |          |      | I/O Thread  | |
+ * |                                 |   |   |          |      |             | |
+ * |                                 |   |   |          ---------> [IOWork]  | |
+ * |                                 |  IPC  |                 |     |       | |
+ * |                                 |   |   |                 |     | (5)   | |
+ * |                                 |   |   |          --------------       | |
+ * |                                 |   |   |          |      |_____________| |
+ * |                                 |   |   |          |                      |
+ * |                                 |   |   |          V                      |
+ * |                                 |   |   |     [HandleResult]              |
+ * |                                 |   |   |          |                      |
+ * |                                 |       |          | (6)                  |
+ * |                                 |  (7)  |          V                      |
+ * |   [SetRequestResult]<---------------------[GetRequestResult]              |
+ * |       |                         |       |                                 |
+ * |       | (8)                     |   |   |                                 |
+ * |       V                         |   |   |                                 |
+ * |[HandlerCallback]                |  IPC  |                                 |
+ * |_______|_________________________|   |   |_________________________________|
+ *         |                             |
+ *         V
+ *        Page
+ *
+ * 1. From the process that is handling the request
+ * Child/Parent (it can be in any process):
+ *   (1) Call FileSystem API from content page with JS. Create a task and run.
+ *   The base constructor [FileSystemTaskChildBase()] of the task should be
+ *   called.
+ *   (2) Forward the task to the parent process through the IPC and call
+ *   [GetRequestParams] to prepare the parameters of the IPC.
+ * Parent:
+ *   (3) The parent process receives IPC and handle it in
+ *   FileystemRequestParent. Get the IPC parameters and create a task to run the
+ *   IPC task.
+ *   (4) The task operation will be performed in the member function of [IOWork].
+ *   A I/O  thread will be created to run that function. If error occurs
+ *   during the operation, call [SetError] to record the error and then abort.
+ *   (5) After finishing the task operation, call [HandleResult] to send the
+ *   result back to the child process though the IPC.
+ *   (6) Call [GetRequestResult] request result to prepare the parameters of the
+ *   IPC. Because the formats of the error result for different task are the
+ *   same, FileSystemTaskChildBase can handle the error message without
+ *   interfering.
+ *   Each task only needs to implement its specific success result preparation
+ *   function -[GetSuccessRequestResult].
+ * Child/Parent:
+ *   (7) The process receives IPC and calls [SetRequestResult] to get the
+ *   task result. Each task needs to implement its specific success result
+ *   parsing function [SetSuccessRequestResult] to get the success result.
+ *   (8) Call [HandlerCallback] to send the task result to the content page.
+ */
+class FileSystemTaskChildBase : public PFileSystemRequestChild
+                              , public nsIIPCBackgroundChildCreateCallback
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIIPCBACKGROUNDCHILDCREATECALLBACK
+
+  /*
+   * Start the task. It will dispatch all the information to the parent process,
+   * PBackground thread. This method must be called from the owning thread.
+   */
+  void
+  Start();
+
+  /*
+   * The error codes are defined in xpcom/base/ErrorList.h and their
+   * corresponding error name and message are defined in dom/base/domerr.msg.
+   */
+  void
+  SetError(const nsresult& aErrorCode);
+
+  FileSystemBase*
+  GetFileSystem() const;
+
+  /*
+   * After the task is completed, this function will be called to pass the task
+   * result to the content page. This method is called in the owning thread.
+   * Override this function to handle the call back to the content page.
+   */
+  virtual void
+  HandlerCallback() = 0;
+
+  bool
+  HasError() const { return NS_FAILED(mErrorValue); }
+
+protected:
+  /*
+   * To create a task to handle the page content request.
+   */
+  explicit FileSystemTaskChildBase(FileSystemBase* aFileSystem);
+
+  virtual
+  ~FileSystemTaskChildBase();
+
+  /*
+   * Wrap the task parameter to FileSystemParams for sending it through IPC.
+   * It will be called when we need to forward a task from the child process to
+   * the parent process. This method runs in the owning thread.
+   * @param filesystem The string representation of the file system.
+   */
+  virtual FileSystemParams
+  GetRequestParams(const nsString& aSerializedDOMPath,
+                   ErrorResult& aRv) const = 0;
+
+  /*
+   * Unwrap the IPC message to get the task success result.
+   * It will be called when the task is completed successfully and an IPC
+   * message is received in the child process and we want to get the task
+   * success result. This method runs in the owning thread.
+   */
+  virtual void
+  SetSuccessRequestResult(const FileSystemResponseValue& aValue,
+                          ErrorResult& aRv) = 0;
+
+  // Overrides PFileSystemRequestChild
+  virtual bool
+  Recv__delete__(const FileSystemResponseValue& value) override;
+
+  nsresult mErrorValue;
+  RefPtr<FileSystemBase> mFileSystem;
+
+private:
+
+  /*
+   * Unwrap the IPC message to get the task result.
+   * It will be called when the task is completed and an IPC message is received
+   * in the content process and we want to get the task result. This runs on the
+   * owning thread.
+   */
+  void
+  SetRequestResult(const FileSystemResponseValue& aValue);
+};
+
+// This class is the 'alter ego' of FileSystemTaskChildBase in the PBackground
+// world.
+class FileSystemTaskParentBase : public Runnable
+{
+public:
+  /*
+   * Start the task. This must be called from the PBackground thread only.
+   */
+  void
+  Start();
+
+  /*
+   * The error codes are defined in xpcom/base/ErrorList.h and their
+   * corresponding error name and message are defined in dom/base/domerr.msg.
+   */
+  void
+  SetError(const nsresult& aErrorCode);
+
+  /*
+   * The function to perform task operation. It will be run on the I/O
+   * thread of the parent process.
+   * Overrides this function to define the task operation for individual task.
+   */
+  virtual nsresult
+  IOWork() = 0;
+
+  /*
+   * Wrap the task success result to FileSystemResponseValue for sending it
+   * through IPC. This method runs in the PBackground thread.
+   * It will be called when the task is completed successfully and we need to
+   * send the task success result back to the child process.
+   */
+  virtual FileSystemResponseValue
+  GetSuccessRequestResult(ErrorResult& aRv) const = 0;
+
+  /*
+   * After finishing the task operation, handle the task result.
+   * If it is an IPC task, send back the IPC result. It runs on the PBackground
+   * thread.
+   */
+  void
+  HandleResult();
+
+  // If this task must do something on the main-thread before IOWork(), it must
+  // overwrite this method. Otherwise it returns true if the FileSystem must be
+  // initialized on the main-thread. It's called from the Background thread.
+  virtual bool
+  NeedToGoToMainThread() const;
+
+  // This method is called only if NeedToGoToMainThread() returns true.
+  // Of course, it runs on the main-thread.
+  virtual nsresult
+  MainThreadWork();
+
+  bool
+  HasError() const { return NS_FAILED(mErrorValue); }
+
+  NS_IMETHOD
+  Run() override;
+
+  virtual nsresult
+  GetTargetPath(nsAString& aPath) const = 0;
+
+private:
+  /*
+   * Wrap the task result to FileSystemResponseValue for sending it through IPC.
+   * It will be called when the task is completed and we need to
+   * send the task result back to the content. This runs on the PBackground
+   * thread.
+   */
+  FileSystemResponseValue
+  GetRequestResult() const;
+
+protected:
+  /*
+   * To create a parent process task delivered from the child process through
+   * IPC.
+   */
+  FileSystemTaskParentBase(FileSystemBase* aFileSystem,
+                           const FileSystemParams& aParam,
+                           FileSystemRequestParent* aParent);
+
+  virtual
+  ~FileSystemTaskParentBase();
+
+  nsresult mErrorValue;
+  RefPtr<FileSystemBase> mFileSystem;
+  RefPtr<FileSystemRequestParent> mRequestParent;
+  nsCOMPtr<nsIEventTarget> mBackgroundEventTarget;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileSystemTaskBase_h
diff --git a/dom/filesystem/FileSystemUtils.cpp b/dom/filesystem/FileSystemUtils.cpp
new file mode 100644
index 000000000..872e049ee
--- /dev/null
+++ b/dom/filesystem/FileSystemUtils.cpp
@@ -0,0 +1,75 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/FileSystemUtils.h"
+
+namespace mozilla {
+namespace dom {
+
+namespace {
+
+bool
+TokenizerIgnoreNothing(char16_t /* aChar */)
+{
+  return false;
+}
+
+} // anonymous namespace
+
+/* static */ bool
+FileSystemUtils::IsDescendantPath(const nsAString& aPath,
+                                  const nsAString& aDescendantPath)
+{
+  // Check the sub-directory path to see if it has the parent path as prefix.
+  if (!aDescendantPath.Equals(aPath) &&
+      !StringBeginsWith(aDescendantPath, aPath)) {
+    return false;
+  }
+
+  return true;
+}
+
+/* static */ bool
+FileSystemUtils::IsValidRelativeDOMPath(const nsAString& aPath,
+                                        nsTArray<nsString>& aParts)
+{
+  // We don't allow empty relative path to access the root.
+  if (aPath.IsEmpty()) {
+    return false;
+  }
+
+  // Leading and trailing "/" are not allowed.
+  if (aPath.First() == FILESYSTEM_DOM_PATH_SEPARATOR_CHAR ||
+      aPath.Last() == FILESYSTEM_DOM_PATH_SEPARATOR_CHAR) {
+    return false;
+  }
+
+  NS_NAMED_LITERAL_STRING(kCurrentDir, ".");
+  NS_NAMED_LITERAL_STRING(kParentDir, "..");
+
+  // Split path and check each path component.
+  nsCharSeparatedTokenizerTemplate<TokenizerIgnoreNothing>
+    tokenizer(aPath, FILESYSTEM_DOM_PATH_SEPARATOR_CHAR);
+
+  while (tokenizer.hasMoreTokens()) {
+    nsDependentSubstring pathComponent = tokenizer.nextToken();
+    // The path containing empty components, such as "foo//bar", is invalid.
+    // We don't allow paths, such as "../foo", "foo/./bar" and "foo/../bar",
+    // to walk up the directory.
+    if (pathComponent.IsEmpty() ||
+        pathComponent.Equals(kCurrentDir) ||
+        pathComponent.Equals(kParentDir)) {
+      return false;
+    }
+
+    aParts.AppendElement(pathComponent);
+  }
+
+  return true;
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/filesystem/FileSystemUtils.h b/dom/filesystem/FileSystemUtils.h
new file mode 100644
index 000000000..ae302e07c
--- /dev/null
+++ b/dom/filesystem/FileSystemUtils.h
@@ -0,0 +1,44 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystemUtils_h
+#define mozilla_dom_FileSystemUtils_h
+
+class nsIFile;
+
+namespace mozilla {
+namespace dom {
+
+#define FILESYSTEM_DOM_PATH_SEPARATOR_LITERAL "/"
+#define FILESYSTEM_DOM_PATH_SEPARATOR_CHAR '/'
+
+/*
+ * This class is for error handling.
+ * All methods in this class are static.
+ */
+class FileSystemUtils
+{
+public:
+  /*
+   * Return true if aDescendantPath is a descendant of aPath.
+   */
+  static bool
+  IsDescendantPath(const nsAString& aPath,
+                   const nsAString& aDescendantPath);
+
+  /**
+   * Return true if this is valid DOMPath. It also splits the path in
+   * subdirectories and stores them in aParts.
+   */
+  static bool
+  IsValidRelativeDOMPath(const nsAString& aPath,
+                         nsTArray<nsString>& aParts);
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileSystemUtils_h
diff --git a/dom/filesystem/GetDirectoryListingTask.cpp b/dom/filesystem/GetDirectoryListingTask.cpp
new file mode 100644
index 000000000..e3ac2933f
--- /dev/null
+++ b/dom/filesystem/GetDirectoryListingTask.cpp
@@ -0,0 +1,390 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GetDirectoryListingTask.h"
+
+#include "HTMLSplitOnSpacesTokenizer.h"
+#include "js/Value.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/dom/FileSystemBase.h"
+#include "mozilla/dom/FileSystemUtils.h"
+#include "mozilla/dom/PFileSystemParams.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/UnionTypes.h"
+#include "mozilla/dom/ipc/BlobChild.h"
+#include "mozilla/dom/ipc/BlobParent.h"
+#include "nsIFile.h"
+#include "nsISimpleEnumerator.h"
+#include "nsStringGlue.h"
+
+namespace mozilla {
+namespace dom {
+
+/**
+ * GetDirectoryListingTaskChild
+ */
+
+/* static */ already_AddRefed<GetDirectoryListingTaskChild>
+GetDirectoryListingTaskChild::Create(FileSystemBase* aFileSystem,
+                                     Directory* aDirectory,
+                                     nsIFile* aTargetPath,
+                                     const nsAString& aFilters,
+                                     ErrorResult& aRv)
+{
+  MOZ_ASSERT(aFileSystem);
+  MOZ_ASSERT(aDirectory);
+  aFileSystem->AssertIsOnOwningThread();
+
+  RefPtr<GetDirectoryListingTaskChild> task =
+    new GetDirectoryListingTaskChild(aFileSystem, aDirectory, aTargetPath,
+                                     aFilters);
+
+  // aTargetPath can be null. In this case SetError will be called.
+
+  nsCOMPtr<nsIGlobalObject> globalObject =
+    do_QueryInterface(aFileSystem->GetParentObject());
+  if (NS_WARN_IF(!globalObject)) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+
+  task->mPromise = Promise::Create(globalObject, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  return task.forget();
+}
+
+GetDirectoryListingTaskChild::GetDirectoryListingTaskChild(FileSystemBase* aFileSystem,
+                                                           Directory* aDirectory,
+                                                           nsIFile* aTargetPath,
+                                                           const nsAString& aFilters)
+  : FileSystemTaskChildBase(aFileSystem)
+  , mDirectory(aDirectory)
+  , mTargetPath(aTargetPath)
+  , mFilters(aFilters)
+{
+  MOZ_ASSERT(aFileSystem);
+  aFileSystem->AssertIsOnOwningThread();
+}
+
+GetDirectoryListingTaskChild::~GetDirectoryListingTaskChild()
+{
+  mFileSystem->AssertIsOnOwningThread();
+}
+
+already_AddRefed<Promise>
+GetDirectoryListingTaskChild::GetPromise()
+{
+  mFileSystem->AssertIsOnOwningThread();
+  return RefPtr<Promise>(mPromise).forget();
+}
+
+FileSystemParams
+GetDirectoryListingTaskChild::GetRequestParams(const nsString& aSerializedDOMPath,
+                                               ErrorResult& aRv) const
+{
+  mFileSystem->AssertIsOnOwningThread();
+
+  // this is the real path.
+  nsAutoString path;
+  aRv = mTargetPath->GetPath(path);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return FileSystemGetDirectoryListingParams();
+  }
+
+  // this is the dom path.
+  nsAutoString directoryPath;
+  mDirectory->GetPath(directoryPath, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return FileSystemGetDirectoryListingParams();
+  }
+
+  return FileSystemGetDirectoryListingParams(aSerializedDOMPath, path,
+                                             directoryPath, mFilters);
+}
+
+void
+GetDirectoryListingTaskChild::SetSuccessRequestResult(const FileSystemResponseValue& aValue,
+                                                      ErrorResult& aRv)
+{
+  mFileSystem->AssertIsOnOwningThread();
+  MOZ_ASSERT(aValue.type() ==
+               FileSystemResponseValue::TFileSystemDirectoryListingResponse);
+
+  FileSystemDirectoryListingResponse r = aValue;
+  for (uint32_t i = 0; i < r.data().Length(); ++i) {
+    const FileSystemDirectoryListingResponseData& data = r.data()[i];
+
+    OwningFileOrDirectory* ofd = mTargetData.AppendElement(fallible);
+    if (!ofd) {
+      aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+      return;
+    }
+
+    if (data.type() == FileSystemDirectoryListingResponseData::TFileSystemDirectoryListingResponseFile) {
+      const FileSystemDirectoryListingResponseFile& d =
+        data.get_FileSystemDirectoryListingResponseFile();
+
+      RefPtr<BlobImpl> blobImpl =
+        static_cast<BlobChild*>(d.blobChild())->GetBlobImpl();
+      MOZ_ASSERT(blobImpl);
+
+      RefPtr<File> file = File::Create(mFileSystem->GetParentObject(), blobImpl);
+      MOZ_ASSERT(file);
+
+      ofd->SetAsFile() = file;
+    } else {
+      MOZ_ASSERT(data.type() == FileSystemDirectoryListingResponseData::TFileSystemDirectoryListingResponseDirectory);
+      const FileSystemDirectoryListingResponseDirectory& d =
+        data.get_FileSystemDirectoryListingResponseDirectory();
+
+      nsCOMPtr<nsIFile> path;
+      aRv = NS_NewLocalFile(d.directoryRealPath(), true, getter_AddRefs(path));
+      if (NS_WARN_IF(aRv.Failed())) {
+        return;
+      }
+
+      RefPtr<Directory> directory =
+        Directory::Create(mFileSystem->GetParentObject(), path, mFileSystem);
+      MOZ_ASSERT(directory);
+
+      ofd->SetAsDirectory() = directory;
+    }
+  }
+}
+
+void
+GetDirectoryListingTaskChild::HandlerCallback()
+{
+  mFileSystem->AssertIsOnOwningThread();
+
+  if (mFileSystem->IsShutdown()) {
+    mPromise = nullptr;
+    return;
+  }
+
+  if (HasError()) {
+    mPromise->MaybeReject(mErrorValue);
+    mPromise = nullptr;
+    return;
+  }
+
+  mPromise->MaybeResolve(mTargetData);
+  mPromise = nullptr;
+}
+
+/**
+ * GetDirectoryListingTaskParent
+ */
+
+/* static */ already_AddRefed<GetDirectoryListingTaskParent>
+GetDirectoryListingTaskParent::Create(FileSystemBase* aFileSystem,
+                                      const FileSystemGetDirectoryListingParams& aParam,
+                                      FileSystemRequestParent* aParent,
+                                      ErrorResult& aRv)
+{
+  MOZ_ASSERT(XRE_IsParentProcess(), "Only call from parent process!");
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aFileSystem);
+
+  RefPtr<GetDirectoryListingTaskParent> task =
+    new GetDirectoryListingTaskParent(aFileSystem, aParam, aParent);
+
+  aRv = NS_NewLocalFile(aParam.realPath(), true,
+                        getter_AddRefs(task->mTargetPath));
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  return task.forget();
+}
+
+GetDirectoryListingTaskParent::GetDirectoryListingTaskParent(FileSystemBase* aFileSystem,
+                                                             const FileSystemGetDirectoryListingParams& aParam,
+                                                             FileSystemRequestParent* aParent)
+  : FileSystemTaskParentBase(aFileSystem, aParam, aParent)
+  , mDOMPath(aParam.domPath())
+  , mFilters(aParam.filters())
+{
+  MOZ_ASSERT(XRE_IsParentProcess(), "Only call from parent process!");
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aFileSystem);
+}
+
+FileSystemResponseValue
+GetDirectoryListingTaskParent::GetSuccessRequestResult(ErrorResult& aRv) const
+{
+  AssertIsOnBackgroundThread();
+
+  InfallibleTArray<PBlobParent*> blobs;
+
+  nsTArray<FileSystemDirectoryListingResponseData> inputs;
+
+  for (unsigned i = 0; i < mTargetData.Length(); i++) {
+    if (mTargetData[i].mType == FileOrDirectoryPath::eFilePath) {
+      nsCOMPtr<nsIFile> path;
+      nsresult rv = NS_NewLocalFile(mTargetData[i].mPath, true,
+                                    getter_AddRefs(path));
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return FileSystemErrorResponse(rv);
+      }
+
+      FileSystemDirectoryListingResponseFile fileData;
+      RefPtr<BlobImpl> blobImpl = new BlobImplFile(path);
+
+      nsAutoString filePath;
+      filePath.Assign(mDOMPath);
+
+      // This is specific for unix root filesystem.
+      if (!mDOMPath.EqualsLiteral(FILESYSTEM_DOM_PATH_SEPARATOR_LITERAL)) {
+        filePath.AppendLiteral(FILESYSTEM_DOM_PATH_SEPARATOR_LITERAL);
+      }
+
+      nsAutoString name;
+      blobImpl->GetName(name);
+      filePath.Append(name);
+      blobImpl->SetDOMPath(filePath);
+
+      fileData.blobParent() =
+        BlobParent::GetOrCreate(mRequestParent->Manager(), blobImpl);
+      inputs.AppendElement(fileData);
+    } else {
+      MOZ_ASSERT(mTargetData[i].mType == FileOrDirectoryPath::eDirectoryPath);
+      FileSystemDirectoryListingResponseDirectory directoryData;
+      directoryData.directoryRealPath() = mTargetData[i].mPath;
+      inputs.AppendElement(directoryData);
+    }
+  }
+
+  FileSystemDirectoryListingResponse response;
+  response.data().SwapElements(inputs);
+  return response;
+}
+
+nsresult
+GetDirectoryListingTaskParent::IOWork()
+{
+  MOZ_ASSERT(XRE_IsParentProcess(),
+             "Only call from parent process!");
+  MOZ_ASSERT(!NS_IsMainThread(), "Only call on worker thread!");
+
+  if (mFileSystem->IsShutdown()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  bool exists;
+  nsresult rv = mTargetPath->Exists(&exists);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (!exists) {
+    if (!mFileSystem->ShouldCreateDirectory()) {
+      return NS_ERROR_DOM_FILE_NOT_FOUND_ERR;
+    }
+
+    rv = mTargetPath->Create(nsIFile::DIRECTORY_TYPE, 0777);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  // Get isDirectory.
+  bool isDir;
+  rv = mTargetPath->IsDirectory(&isDir);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (!isDir) {
+    return NS_ERROR_DOM_FILESYSTEM_TYPE_MISMATCH_ERR;
+  }
+
+  nsCOMPtr<nsISimpleEnumerator> entries;
+  rv = mTargetPath->GetDirectoryEntries(getter_AddRefs(entries));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  bool filterOutSensitive = false;
+  {
+    HTMLSplitOnSpacesTokenizer tokenizer(mFilters, ';');
+    nsAutoString token;
+    while (tokenizer.hasMoreTokens()) {
+      token = tokenizer.nextToken();
+      if (token.EqualsLiteral("filter-out-sensitive")) {
+        filterOutSensitive = true;
+      } else {
+        MOZ_CRASH("Unrecognized filter");
+      }
+    }
+  }
+
+  for (;;) {
+    bool hasMore = false;
+    if (NS_WARN_IF(NS_FAILED(entries->HasMoreElements(&hasMore))) || !hasMore) {
+      break;
+    }
+    nsCOMPtr<nsISupports> supp;
+    if (NS_WARN_IF(NS_FAILED(entries->GetNext(getter_AddRefs(supp))))) {
+      break;
+    }
+
+    nsCOMPtr<nsIFile> currFile = do_QueryInterface(supp);
+    MOZ_ASSERT(currFile);
+
+    bool isSpecial, isFile;
+    if (NS_WARN_IF(NS_FAILED(currFile->IsSpecial(&isSpecial))) ||
+        isSpecial) {
+      continue;
+    }
+    if (NS_WARN_IF(NS_FAILED(currFile->IsFile(&isFile)) ||
+                   NS_FAILED(currFile->IsDirectory(&isDir))) ||
+        !(isFile || isDir)) {
+      continue;
+    }
+
+    if (filterOutSensitive) {
+      bool isHidden;
+      if (NS_WARN_IF(NS_FAILED(currFile->IsHidden(&isHidden))) || isHidden) {
+        continue;
+      }
+      nsAutoString leafName;
+      if (NS_WARN_IF(NS_FAILED(currFile->GetLeafName(leafName)))) {
+        continue;
+      }
+      if (leafName[0] == char16_t('.')) {
+        continue;
+      }
+    }
+
+    nsAutoString path;
+    if (NS_WARN_IF(NS_FAILED(currFile->GetPath(path)))) {
+      continue;
+    }
+
+    FileOrDirectoryPath element;
+    element.mPath = path;
+    element.mType = isDir ? FileOrDirectoryPath::eDirectoryPath
+                          : FileOrDirectoryPath::eFilePath;
+
+    if (!mTargetData.AppendElement(element, fallible)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+  }
+  return NS_OK;
+}
+
+nsresult
+GetDirectoryListingTaskParent::GetTargetPath(nsAString& aPath) const
+{
+  return mTargetPath->GetPath(aPath);
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/filesystem/GetDirectoryListingTask.h b/dom/filesystem/GetDirectoryListingTask.h
new file mode 100644
index 000000000..7692c8bae
--- /dev/null
+++ b/dom/filesystem/GetDirectoryListingTask.h
@@ -0,0 +1,106 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_GetDirectoryListing_h
+#define mozilla_dom_GetDirectoryListing_h
+
+#include "mozilla/dom/Directory.h"
+#include "mozilla/dom/FileSystemTaskBase.h"
+#include "mozilla/ErrorResult.h"
+
+namespace mozilla {
+namespace dom {
+
+class BlobImpl;
+class FileSystemGetDirectoryListingParams;
+class OwningFileOrDirectory;
+
+class GetDirectoryListingTaskChild final : public FileSystemTaskChildBase
+{
+public:
+  static already_AddRefed<GetDirectoryListingTaskChild>
+  Create(FileSystemBase* aFileSystem,
+         Directory* aDirectory,
+         nsIFile* aTargetPath,
+         const nsAString& aFilters,
+         ErrorResult& aRv);
+
+  virtual
+  ~GetDirectoryListingTaskChild();
+
+  already_AddRefed<Promise>
+  GetPromise();
+
+private:
+  // If aDirectoryOnly is set, we should ensure that the target is a directory.
+  GetDirectoryListingTaskChild(FileSystemBase* aFileSystem,
+                               Directory* aDirectory,
+                               nsIFile* aTargetPath,
+                               const nsAString& aFilters);
+
+  virtual FileSystemParams
+  GetRequestParams(const nsString& aSerializedDOMPath,
+                   ErrorResult& aRv) const override;
+
+  virtual void
+  SetSuccessRequestResult(const FileSystemResponseValue& aValue,
+                          ErrorResult& aRv) override;
+
+  virtual void
+  HandlerCallback() override;
+
+  RefPtr<Promise> mPromise;
+  RefPtr<Directory> mDirectory;
+  nsCOMPtr<nsIFile> mTargetPath;
+  nsString mFilters;
+
+  FallibleTArray<OwningFileOrDirectory> mTargetData;
+};
+
+class GetDirectoryListingTaskParent final : public FileSystemTaskParentBase
+{
+public:
+  static already_AddRefed<GetDirectoryListingTaskParent>
+  Create(FileSystemBase* aFileSystem,
+         const FileSystemGetDirectoryListingParams& aParam,
+         FileSystemRequestParent* aParent,
+         ErrorResult& aRv);
+
+  nsresult
+  GetTargetPath(nsAString& aPath) const override;
+
+private:
+  GetDirectoryListingTaskParent(FileSystemBase* aFileSystem,
+                                const FileSystemGetDirectoryListingParams& aParam,
+                                FileSystemRequestParent* aParent);
+
+  virtual FileSystemResponseValue
+  GetSuccessRequestResult(ErrorResult& aRv) const override;
+
+  virtual nsresult
+  IOWork() override;
+
+  nsCOMPtr<nsIFile> mTargetPath;
+  nsString mDOMPath;
+  nsString mFilters;
+
+  struct FileOrDirectoryPath
+  {
+    nsString mPath;
+
+    enum {
+      eFilePath,
+      eDirectoryPath
+    } mType;
+  };
+
+  FallibleTArray<FileOrDirectoryPath> mTargetData;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_GetDirectoryListing_h
diff --git a/dom/filesystem/GetFileOrDirectoryTask.cpp b/dom/filesystem/GetFileOrDirectoryTask.cpp
new file mode 100644
index 000000000..f71976503
--- /dev/null
+++ b/dom/filesystem/GetFileOrDirectoryTask.cpp
@@ -0,0 +1,280 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GetFileOrDirectoryTask.h"
+
+#include "js/Value.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/dom/FileSystemBase.h"
+#include "mozilla/dom/FileSystemUtils.h"
+#include "mozilla/dom/PFileSystemParams.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/ipc/BlobChild.h"
+#include "mozilla/dom/ipc/BlobParent.h"
+#include "nsIFile.h"
+#include "nsStringGlue.h"
+
+namespace mozilla {
+namespace dom {
+
+/**
+ * GetFileOrDirectoryTaskChild
+ */
+
+/* static */ already_AddRefed<GetFileOrDirectoryTaskChild>
+GetFileOrDirectoryTaskChild::Create(FileSystemBase* aFileSystem,
+                                    nsIFile* aTargetPath,
+                                    ErrorResult& aRv)
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
+  MOZ_ASSERT(aFileSystem);
+
+  RefPtr<GetFileOrDirectoryTaskChild> task =
+    new GetFileOrDirectoryTaskChild(aFileSystem, aTargetPath);
+
+  // aTargetPath can be null. In this case SetError will be called.
+
+  nsCOMPtr<nsIGlobalObject> globalObject =
+    do_QueryInterface(aFileSystem->GetParentObject());
+  if (NS_WARN_IF(!globalObject)) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+
+  task->mPromise = Promise::Create(globalObject, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  return task.forget();
+}
+
+GetFileOrDirectoryTaskChild::GetFileOrDirectoryTaskChild(FileSystemBase* aFileSystem,
+                                                         nsIFile* aTargetPath)
+  : FileSystemTaskChildBase(aFileSystem)
+  , mTargetPath(aTargetPath)
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
+  MOZ_ASSERT(aFileSystem);
+}
+
+GetFileOrDirectoryTaskChild::~GetFileOrDirectoryTaskChild()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+}
+
+already_AddRefed<Promise>
+GetFileOrDirectoryTaskChild::GetPromise()
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
+  return RefPtr<Promise>(mPromise).forget();
+}
+
+FileSystemParams
+GetFileOrDirectoryTaskChild::GetRequestParams(const nsString& aSerializedDOMPath,
+                                              ErrorResult& aRv) const
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
+
+  nsAutoString path;
+  aRv = mTargetPath->GetPath(path);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return FileSystemGetFileOrDirectoryParams();
+  }
+
+  return FileSystemGetFileOrDirectoryParams(aSerializedDOMPath, path);
+}
+
+void
+GetFileOrDirectoryTaskChild::SetSuccessRequestResult(const FileSystemResponseValue& aValue,
+                                                     ErrorResult& aRv)
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
+  switch (aValue.type()) {
+    case FileSystemResponseValue::TFileSystemFileResponse: {
+      FileSystemFileResponse r = aValue;
+
+      RefPtr<BlobImpl> blobImpl =
+        static_cast<BlobChild*>(r.blobChild())->GetBlobImpl();
+      MOZ_ASSERT(blobImpl);
+
+      mResultFile = File::Create(mFileSystem->GetParentObject(), blobImpl);
+      MOZ_ASSERT(mResultFile);
+      break;
+    }
+    case FileSystemResponseValue::TFileSystemDirectoryResponse: {
+      FileSystemDirectoryResponse r = aValue;
+
+      nsCOMPtr<nsIFile> file;
+      aRv = NS_NewLocalFile(r.realPath(), true, getter_AddRefs(file));
+      if (NS_WARN_IF(aRv.Failed())) {
+        return;
+      }
+
+      mResultDirectory = Directory::Create(mFileSystem->GetParentObject(),
+                                           file, mFileSystem);
+      MOZ_ASSERT(mResultDirectory);
+      break;
+    }
+    default: {
+      NS_RUNTIMEABORT("not reached");
+      break;
+    }
+  }
+}
+
+void
+GetFileOrDirectoryTaskChild::HandlerCallback()
+{
+  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
+  if (mFileSystem->IsShutdown()) {
+    mPromise = nullptr;
+    return;
+  }
+
+  if (HasError()) {
+    mPromise->MaybeReject(mErrorValue);
+    mPromise = nullptr;
+    return;
+  }
+
+  if (mResultDirectory) {
+    mPromise->MaybeResolve(mResultDirectory);
+    mResultDirectory = nullptr;
+    mPromise = nullptr;
+    return;
+  }
+
+  MOZ_ASSERT(mResultFile);
+  mPromise->MaybeResolve(mResultFile);
+  mResultFile = nullptr;
+  mPromise = nullptr;
+}
+
+/**
+ * GetFileOrDirectoryTaskParent
+ */
+
+/* static */ already_AddRefed<GetFileOrDirectoryTaskParent>
+GetFileOrDirectoryTaskParent::Create(FileSystemBase* aFileSystem,
+                                     const FileSystemGetFileOrDirectoryParams& aParam,
+                                     FileSystemRequestParent* aParent,
+                                     ErrorResult& aRv)
+{
+  MOZ_ASSERT(XRE_IsParentProcess(), "Only call from parent process!");
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aFileSystem);
+
+  RefPtr<GetFileOrDirectoryTaskParent> task =
+    new GetFileOrDirectoryTaskParent(aFileSystem, aParam, aParent);
+
+  aRv = NS_NewLocalFile(aParam.realPath(), true,
+                        getter_AddRefs(task->mTargetPath));
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  return task.forget();
+}
+
+GetFileOrDirectoryTaskParent::GetFileOrDirectoryTaskParent(FileSystemBase* aFileSystem,
+                                                           const FileSystemGetFileOrDirectoryParams& aParam,
+                                                           FileSystemRequestParent* aParent)
+  : FileSystemTaskParentBase(aFileSystem, aParam, aParent)
+  , mIsDirectory(false)
+{
+  MOZ_ASSERT(XRE_IsParentProcess(), "Only call from parent process!");
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aFileSystem);
+}
+
+FileSystemResponseValue
+GetFileOrDirectoryTaskParent::GetSuccessRequestResult(ErrorResult& aRv) const
+{
+  AssertIsOnBackgroundThread();
+
+  nsAutoString path;
+  aRv = mTargetPath->GetPath(path);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return FileSystemDirectoryResponse();
+  }
+
+  if (mIsDirectory) {
+    return FileSystemDirectoryResponse(path);
+  }
+
+  RefPtr<BlobImpl> blobImpl = new BlobImplFile(mTargetPath);
+  BlobParent* blobParent =
+    BlobParent::GetOrCreate(mRequestParent->Manager(), blobImpl);
+  return FileSystemFileResponse(blobParent, nullptr);
+}
+
+nsresult
+GetFileOrDirectoryTaskParent::IOWork()
+{
+  MOZ_ASSERT(XRE_IsParentProcess(),
+             "Only call from parent process!");
+  MOZ_ASSERT(!NS_IsMainThread(), "Only call on worker thread!");
+
+  if (mFileSystem->IsShutdown()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Whether we want to get the root directory.
+  bool exists;
+  nsresult rv = mTargetPath->Exists(&exists);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (!exists) {
+    if (!mFileSystem->ShouldCreateDirectory()) {
+      return NS_ERROR_DOM_FILE_NOT_FOUND_ERR;
+    }
+
+    rv = mTargetPath->Create(nsIFile::DIRECTORY_TYPE, 0777);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  // Get isDirectory.
+  rv = mTargetPath->IsDirectory(&mIsDirectory);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (mIsDirectory) {
+    return NS_OK;
+  }
+
+  bool isFile;
+  // Get isFile
+  rv = mTargetPath->IsFile(&isFile);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (!isFile) {
+    // Neither directory or file.
+    return NS_ERROR_DOM_FILESYSTEM_TYPE_MISMATCH_ERR;
+  }
+
+  if (!mFileSystem->IsSafeFile(mTargetPath)) {
+    return NS_ERROR_DOM_SECURITY_ERR;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+GetFileOrDirectoryTaskParent::GetTargetPath(nsAString& aPath) const
+{
+  return mTargetPath->GetPath(aPath);
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/filesystem/GetFileOrDirectoryTask.h b/dom/filesystem/GetFileOrDirectoryTask.h
new file mode 100644
index 000000000..2a53df158
--- /dev/null
+++ b/dom/filesystem/GetFileOrDirectoryTask.h
@@ -0,0 +1,89 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_GetFileOrDirectory_h
+#define mozilla_dom_GetFileOrDirectory_h
+
+#include "mozilla/dom/Directory.h"
+#include "mozilla/dom/FileSystemTaskBase.h"
+#include "mozilla/ErrorResult.h"
+
+namespace mozilla {
+namespace dom {
+
+class BlobImpl;
+class FileSystemGetFileOrDirectoryParams;
+
+class GetFileOrDirectoryTaskChild final : public FileSystemTaskChildBase
+{
+public:
+  static already_AddRefed<GetFileOrDirectoryTaskChild>
+  Create(FileSystemBase* aFileSystem,
+         nsIFile* aTargetPath,
+         ErrorResult& aRv);
+
+  virtual
+  ~GetFileOrDirectoryTaskChild();
+
+  already_AddRefed<Promise>
+  GetPromise();
+
+protected:
+  virtual FileSystemParams
+  GetRequestParams(const nsString& aSerializedDOMPath,
+                   ErrorResult& aRv) const override;
+
+  virtual void
+  SetSuccessRequestResult(const FileSystemResponseValue& aValue,
+                          ErrorResult& aRv) override;
+  virtual void
+  HandlerCallback() override;
+
+private:
+  GetFileOrDirectoryTaskChild(FileSystemBase* aFileSystem,
+                              nsIFile* aTargetPath);
+
+  RefPtr<Promise> mPromise;
+  nsCOMPtr<nsIFile> mTargetPath;
+
+  RefPtr<File> mResultFile;
+  RefPtr<Directory> mResultDirectory;
+};
+
+class GetFileOrDirectoryTaskParent final : public FileSystemTaskParentBase
+{
+public:
+  static already_AddRefed<GetFileOrDirectoryTaskParent>
+  Create(FileSystemBase* aFileSystem,
+         const FileSystemGetFileOrDirectoryParams& aParam,
+         FileSystemRequestParent* aParent,
+         ErrorResult& aRv);
+
+  nsresult
+  GetTargetPath(nsAString& aPath) const override;
+
+protected:
+  virtual FileSystemResponseValue
+  GetSuccessRequestResult(ErrorResult& aRv) const override;
+
+  virtual nsresult
+  IOWork() override;
+
+private:
+  GetFileOrDirectoryTaskParent(FileSystemBase* aFileSystem,
+                               const FileSystemGetFileOrDirectoryParams& aParam,
+                               FileSystemRequestParent* aParent);
+
+  nsCOMPtr<nsIFile> mTargetPath;
+
+  // Whether we get a directory.
+  bool mIsDirectory;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_GetFileOrDirectory_h
diff --git a/dom/filesystem/GetFilesHelper.cpp b/dom/filesystem/GetFilesHelper.cpp
new file mode 100644
index 000000000..21d228a60
--- /dev/null
+++ b/dom/filesystem/GetFilesHelper.cpp
@@ -0,0 +1,643 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GetFilesHelper.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/dom/ContentParent.h"
+#include "nsProxyRelease.h"
+
+namespace mozilla {
+namespace dom {
+
+namespace {
+
+// This class is used in the DTOR of GetFilesHelper to release resources in the
+// correct thread.
+class ReleaseRunnable final : public Runnable
+{
+public:
+  static void
+  MaybeReleaseOnMainThread(nsTArray<RefPtr<Promise>>& aPromises,
+                           nsTArray<RefPtr<GetFilesCallback>>& aCallbacks,
+                           Sequence<RefPtr<File>>& aFiles,
+                           already_AddRefed<nsIGlobalObject> aGlobal)
+  {
+    nsCOMPtr<nsIGlobalObject> global(aGlobal);
+    if (NS_IsMainThread()) {
+      return;
+    }
+
+    RefPtr<ReleaseRunnable> runnable =
+      new ReleaseRunnable(aPromises, aCallbacks, aFiles, global.forget());
+    NS_DispatchToMainThread(runnable);
+  }
+
+  NS_IMETHOD
+  Run() override
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+
+    mPromises.Clear();
+    mCallbacks.Clear();
+    mFiles.Clear();
+    mGlobal = nullptr;
+
+    return NS_OK;
+  }
+
+private:
+  ReleaseRunnable(nsTArray<RefPtr<Promise>>& aPromises,
+                  nsTArray<RefPtr<GetFilesCallback>>& aCallbacks,
+                  Sequence<RefPtr<File>>& aFiles,
+                  already_AddRefed<nsIGlobalObject> aGlobal)
+  {
+    mPromises.SwapElements(aPromises);
+    mCallbacks.SwapElements(aCallbacks);
+    mFiles.SwapElements(aFiles);
+    mGlobal = aGlobal;
+  }
+
+  nsTArray<RefPtr<Promise>> mPromises;
+  nsTArray<RefPtr<GetFilesCallback>> mCallbacks;
+  Sequence<RefPtr<File>> mFiles;
+  nsCOMPtr<nsIGlobalObject> mGlobal;
+};
+
+} // anonymous
+
+///////////////////////////////////////////////////////////////////////////////
+// GetFilesHelper Base class
+
+already_AddRefed<GetFilesHelper>
+GetFilesHelper::Create(nsIGlobalObject* aGlobal,
+                       const nsTArray<OwningFileOrDirectory>& aFilesOrDirectory,
+                       bool aRecursiveFlag, ErrorResult& aRv)
+{
+  RefPtr<GetFilesHelper> helper;
+
+  if (XRE_IsParentProcess()) {
+    helper = new GetFilesHelper(aGlobal, aRecursiveFlag);
+  } else {
+    helper = new GetFilesHelperChild(aGlobal, aRecursiveFlag);
+  }
+
+  nsAutoString directoryPath;
+
+  for (uint32_t i = 0; i < aFilesOrDirectory.Length(); ++i) {
+    const OwningFileOrDirectory& data = aFilesOrDirectory[i];
+    if (data.IsFile()) {
+      if (!helper->mFiles.AppendElement(data.GetAsFile(), fallible)) {
+        aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+        return nullptr;
+      }
+    } else {
+      MOZ_ASSERT(data.IsDirectory());
+
+      // We support the upload of only 1 top-level directory from our
+      // directory picker. This means that we cannot have more than 1
+      // Directory object in aFilesOrDirectory array.
+      MOZ_ASSERT(directoryPath.IsEmpty());
+
+      RefPtr<Directory> directory = data.GetAsDirectory();
+      MOZ_ASSERT(directory);
+
+      aRv = directory->GetFullRealPath(directoryPath);
+      if (NS_WARN_IF(aRv.Failed())) {
+        return nullptr;
+      }
+    }
+  }
+
+  // No directories to explore.
+  if (directoryPath.IsEmpty()) {
+    helper->mListingCompleted = true;
+    return helper.forget();
+  }
+
+  MOZ_ASSERT(helper->mFiles.IsEmpty());
+  helper->SetDirectoryPath(directoryPath);
+
+  helper->Work(aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  return helper.forget();
+}
+
+GetFilesHelper::GetFilesHelper(nsIGlobalObject* aGlobal, bool aRecursiveFlag)
+  : GetFilesHelperBase(aRecursiveFlag)
+  , mGlobal(aGlobal)
+  , mListingCompleted(false)
+  , mErrorResult(NS_OK)
+  , mMutex("GetFilesHelper::mMutex")
+  , mCanceled(false)
+{
+}
+
+GetFilesHelper::~GetFilesHelper()
+{
+  ReleaseRunnable::MaybeReleaseOnMainThread(mPromises, mCallbacks, mFiles,
+                                            mGlobal.forget());
+}
+
+void
+GetFilesHelper::AddPromise(Promise* aPromise)
+{
+  MOZ_ASSERT(aPromise);
+
+  // Still working.
+  if (!mListingCompleted) {
+    mPromises.AppendElement(aPromise);
+    return;
+  }
+
+  MOZ_ASSERT(mPromises.IsEmpty());
+  ResolveOrRejectPromise(aPromise);
+}
+
+void
+GetFilesHelper::AddCallback(GetFilesCallback* aCallback)
+{
+  MOZ_ASSERT(aCallback);
+
+  // Still working.
+  if (!mListingCompleted) {
+    mCallbacks.AppendElement(aCallback);
+    return;
+  }
+
+  MOZ_ASSERT(mCallbacks.IsEmpty());
+  RunCallback(aCallback);
+}
+
+void
+GetFilesHelper::Unlink()
+{
+  mGlobal = nullptr;
+  mFiles.Clear();
+  mPromises.Clear();
+  mCallbacks.Clear();
+
+  {
+    MutexAutoLock lock(mMutex);
+    mCanceled = true;
+  }
+
+  Cancel();
+}
+
+void
+GetFilesHelper::Traverse(nsCycleCollectionTraversalCallback &cb)
+{
+  GetFilesHelper* tmp = this;
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mGlobal);
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFiles);
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPromises);
+}
+
+void
+GetFilesHelper::Work(ErrorResult& aRv)
+{
+  nsCOMPtr<nsIEventTarget> target =
+    do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
+  MOZ_ASSERT(target);
+
+  aRv = target->Dispatch(this, NS_DISPATCH_NORMAL);
+}
+
+NS_IMETHODIMP
+GetFilesHelper::Run()
+{
+  MOZ_ASSERT(!mDirectoryPath.IsEmpty());
+  MOZ_ASSERT(!mListingCompleted);
+
+  // First step is to retrieve the list of file paths.
+  // This happens in the I/O thread.
+  if (!NS_IsMainThread()) {
+    RunIO();
+
+    // If this operation has been canceled, we don't have to go back to
+    // main-thread.
+    if (IsCanceled()) {
+      return NS_OK;
+    }
+
+    return NS_DispatchToMainThread(this);
+  }
+
+  // We are here, but we should not do anything on this thread because, in the
+  // meantime, the operation has been canceled.
+  if (IsCanceled()) {
+    return NS_OK;
+  }
+
+  RunMainThread();
+
+  OperationCompleted();
+  return NS_OK;
+}
+
+void
+GetFilesHelper::OperationCompleted()
+{
+  // We mark the operation as completed here.
+  mListingCompleted = true;
+
+  // Let's process the pending promises.
+  nsTArray<RefPtr<Promise>> promises;
+  promises.SwapElements(mPromises);
+
+  for (uint32_t i = 0; i < promises.Length(); ++i) {
+    ResolveOrRejectPromise(promises[i]);
+  }
+
+  // Let's process the pending callbacks.
+  nsTArray<RefPtr<GetFilesCallback>> callbacks;
+  callbacks.SwapElements(mCallbacks);
+
+  for (uint32_t i = 0; i < callbacks.Length(); ++i) {
+    RunCallback(callbacks[i]);
+  }
+}
+
+void
+GetFilesHelper::RunIO()
+{
+  MOZ_ASSERT(!NS_IsMainThread());
+  MOZ_ASSERT(!mDirectoryPath.IsEmpty());
+  MOZ_ASSERT(!mListingCompleted);
+
+  nsCOMPtr<nsIFile> file;
+  mErrorResult = NS_NewLocalFile(mDirectoryPath, true, getter_AddRefs(file));
+  if (NS_WARN_IF(NS_FAILED(mErrorResult))) {
+    return;
+  }
+
+  nsAutoString leafName;
+  mErrorResult = file->GetLeafName(leafName);
+  if (NS_WARN_IF(NS_FAILED(mErrorResult))) {
+    return;
+  }
+
+  nsAutoString domPath;
+  domPath.AssignLiteral(FILESYSTEM_DOM_PATH_SEPARATOR_LITERAL);
+  domPath.Append(leafName);
+
+  mErrorResult = ExploreDirectory(domPath, file);
+}
+
+void
+GetFilesHelper::RunMainThread()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!mDirectoryPath.IsEmpty());
+  MOZ_ASSERT(!mListingCompleted);
+
+  // If there is an error, do nothing.
+  if (NS_FAILED(mErrorResult)) {
+    return;
+  }
+
+  // Create the sequence of Files.
+  for (uint32_t i = 0; i < mTargetBlobImplArray.Length(); ++i) {
+    RefPtr<File> domFile = File::Create(mGlobal, mTargetBlobImplArray[i]);
+    MOZ_ASSERT(domFile);
+
+    if (!mFiles.AppendElement(domFile, fallible)) {
+      mErrorResult = NS_ERROR_OUT_OF_MEMORY;
+      mFiles.Clear();
+      return;
+    }
+  }
+}
+
+nsresult
+GetFilesHelperBase::ExploreDirectory(const nsAString& aDOMPath, nsIFile* aFile)
+{
+  MOZ_ASSERT(!NS_IsMainThread());
+  MOZ_ASSERT(aFile);
+
+  // We check if this operation has to be terminated at each recursion.
+  if (IsCanceled()) {
+    return NS_OK;
+  }
+
+  nsresult rv = AddExploredDirectory(aFile);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsCOMPtr<nsISimpleEnumerator> entries;
+  rv = aFile->GetDirectoryEntries(getter_AddRefs(entries));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  for (;;) {
+    bool hasMore = false;
+    if (NS_WARN_IF(NS_FAILED(entries->HasMoreElements(&hasMore))) || !hasMore) {
+      break;
+    }
+
+    nsCOMPtr<nsISupports> supp;
+    if (NS_WARN_IF(NS_FAILED(entries->GetNext(getter_AddRefs(supp))))) {
+      break;
+    }
+
+    nsCOMPtr<nsIFile> currFile = do_QueryInterface(supp);
+    MOZ_ASSERT(currFile);
+
+    bool isLink, isSpecial, isFile, isDir;
+    if (NS_WARN_IF(NS_FAILED(currFile->IsSymlink(&isLink)) ||
+                   NS_FAILED(currFile->IsSpecial(&isSpecial))) ||
+        isSpecial) {
+      continue;
+    }
+
+    if (NS_WARN_IF(NS_FAILED(currFile->IsFile(&isFile)) ||
+                   NS_FAILED(currFile->IsDirectory(&isDir))) ||
+        !(isFile || isDir)) {
+      continue;
+    }
+
+    // We don't want to explore loops of links.
+    if (isDir && isLink && !ShouldFollowSymLink(currFile)) {
+      continue;
+    }
+
+    // The new domPath
+    nsAutoString domPath;
+    domPath.Assign(aDOMPath);
+    if (!aDOMPath.EqualsLiteral(FILESYSTEM_DOM_PATH_SEPARATOR_LITERAL)) {
+      domPath.AppendLiteral(FILESYSTEM_DOM_PATH_SEPARATOR_LITERAL);
+    }
+
+    nsAutoString leafName;
+    if (NS_WARN_IF(NS_FAILED(currFile->GetLeafName(leafName)))) {
+      continue;
+    }
+    domPath.Append(leafName);
+
+    if (isFile) {
+      RefPtr<BlobImpl> blobImpl = new BlobImplFile(currFile);
+      blobImpl->SetDOMPath(domPath);
+
+      if (!mTargetBlobImplArray.AppendElement(blobImpl, fallible)) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+
+      continue;
+    }
+
+    MOZ_ASSERT(isDir);
+    if (!mRecursiveFlag) {
+      continue;
+    }
+
+    // Recursive.
+    rv = ExploreDirectory(domPath, currFile);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  return NS_OK;
+}
+
+nsresult
+GetFilesHelperBase::AddExploredDirectory(nsIFile* aDir)
+{
+  nsresult rv;
+
+#ifdef DEBUG
+  bool isDir;
+  rv = aDir->IsDirectory(&isDir);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  MOZ_ASSERT(isDir, "Why are we here?");
+#endif
+
+  bool isLink;
+  rv = aDir->IsSymlink(&isLink);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsAutoCString path;
+
+  if (!isLink) {
+    nsAutoString path16;
+    rv = aDir->GetPath(path16);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+
+    path = NS_ConvertUTF16toUTF8(path16);
+  } else {
+    rv = aDir->GetNativeTarget(path);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  mExploredDirectories.PutEntry(path);
+  return NS_OK;
+}
+
+bool
+GetFilesHelperBase::ShouldFollowSymLink(nsIFile* aDir)
+{
+#ifdef DEBUG
+  bool isLink, isDir;
+  if (NS_WARN_IF(NS_FAILED(aDir->IsSymlink(&isLink)) ||
+                 NS_FAILED(aDir->IsDirectory(&isDir)))) {
+    return false;
+  }
+
+  MOZ_ASSERT(isLink && isDir, "Why are we here?");
+#endif
+
+  nsAutoCString targetPath;
+  if (NS_WARN_IF(NS_FAILED(aDir->GetNativeTarget(targetPath)))) {
+    return false;
+  }
+
+  return !mExploredDirectories.Contains(targetPath);
+}
+
+void
+GetFilesHelper::ResolveOrRejectPromise(Promise* aPromise)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mListingCompleted);
+  MOZ_ASSERT(aPromise);
+
+  // Error propagation.
+  if (NS_FAILED(mErrorResult)) {
+    aPromise->MaybeReject(mErrorResult);
+    return;
+  }
+
+  aPromise->MaybeResolve(mFiles);
+}
+
+void
+GetFilesHelper::RunCallback(GetFilesCallback* aCallback)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mListingCompleted);
+  MOZ_ASSERT(aCallback);
+
+  aCallback->Callback(mErrorResult, mFiles);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// GetFilesHelperChild class
+
+void
+GetFilesHelperChild::Work(ErrorResult& aRv)
+{
+  ContentChild* cc = ContentChild::GetSingleton();
+  if (NS_WARN_IF(!cc)) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return;
+  }
+
+  aRv = nsContentUtils::GenerateUUIDInPlace(mUUID);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return;
+  }
+
+  mPendingOperation = true;
+  cc->CreateGetFilesRequest(mDirectoryPath, mRecursiveFlag, mUUID, this);
+}
+
+void
+GetFilesHelperChild::Cancel()
+{
+  if (!mPendingOperation) {
+    return;
+  }
+
+  ContentChild* cc = ContentChild::GetSingleton();
+  if (NS_WARN_IF(!cc)) {
+    return;
+  }
+
+  mPendingOperation = false;
+  cc->DeleteGetFilesRequest(mUUID, this);
+}
+
+bool
+GetFilesHelperChild::AppendBlobImpl(BlobImpl* aBlobImpl)
+{
+  MOZ_ASSERT(mPendingOperation);
+  MOZ_ASSERT(aBlobImpl);
+  MOZ_ASSERT(aBlobImpl->IsFile());
+
+  RefPtr<File> file = File::Create(mGlobal, aBlobImpl);
+  MOZ_ASSERT(file);
+
+  return mFiles.AppendElement(file, fallible);
+}
+
+void
+GetFilesHelperChild::Finished(nsresult aError)
+{
+  MOZ_ASSERT(mPendingOperation);
+  MOZ_ASSERT(NS_SUCCEEDED(mErrorResult));
+
+  mPendingOperation = false;
+  mErrorResult = aError;
+
+  OperationCompleted();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// GetFilesHelperParent class
+
+class GetFilesHelperParentCallback final : public GetFilesCallback
+{
+public:
+  explicit GetFilesHelperParentCallback(GetFilesHelperParent* aParent)
+    : mParent(aParent)
+  {
+    MOZ_ASSERT(aParent);
+  }
+
+  void
+  Callback(nsresult aStatus, const Sequence<RefPtr<File>>& aFiles) override
+  {
+    if (NS_FAILED(aStatus)) {
+      mParent->mContentParent->SendGetFilesResponseAndForget(mParent->mUUID,
+                                                             GetFilesResponseFailure(aStatus));
+      return;
+    }
+
+    GetFilesResponseSuccess success;
+    nsTArray<PBlobParent*>& blobsParent = success.blobsParent();
+    blobsParent.SetLength(aFiles.Length());
+
+    for (uint32_t i = 0; i < aFiles.Length(); ++i) {
+      blobsParent[i] =
+        mParent->mContentParent->GetOrCreateActorForBlob(aFiles[i]);
+      if (!blobsParent[i]) {
+        mParent->mContentParent->SendGetFilesResponseAndForget(mParent->mUUID,
+                                                               GetFilesResponseFailure(NS_ERROR_OUT_OF_MEMORY));
+        return;
+      }
+    }
+
+    mParent->mContentParent->SendGetFilesResponseAndForget(mParent->mUUID,
+                                                           success);
+  }
+
+private:
+  // Raw pointer because this callback is kept alive by this parent object.
+  GetFilesHelperParent* mParent;
+};
+
+GetFilesHelperParent::GetFilesHelperParent(const nsID& aUUID,
+                                           ContentParent* aContentParent,
+                                           bool aRecursiveFlag)
+  : GetFilesHelper(nullptr, aRecursiveFlag)
+  , mContentParent(aContentParent)
+  , mUUID(aUUID)
+{}
+
+GetFilesHelperParent::~GetFilesHelperParent()
+{
+  NS_ReleaseOnMainThread(mContentParent.forget());
+}
+
+/* static */ already_AddRefed<GetFilesHelperParent>
+GetFilesHelperParent::Create(const nsID& aUUID, const nsAString& aDirectoryPath,
+                             bool aRecursiveFlag, ContentParent* aContentParent,
+                             ErrorResult& aRv)
+{
+  MOZ_ASSERT(aContentParent);
+
+  RefPtr<GetFilesHelperParent> helper =
+    new GetFilesHelperParent(aUUID, aContentParent, aRecursiveFlag);
+  helper->SetDirectoryPath(aDirectoryPath);
+
+  helper->Work(aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  RefPtr<GetFilesHelperParentCallback> callback =
+    new GetFilesHelperParentCallback(helper);
+  helper->AddCallback(callback);
+
+  return helper.forget();
+}
+
+} // dom namespace
+} // mozilla namespace
diff --git a/dom/filesystem/GetFilesHelper.h b/dom/filesystem/GetFilesHelper.h
new file mode 100644
index 000000000..a1bb1b27a
--- /dev/null
+++ b/dom/filesystem/GetFilesHelper.h
@@ -0,0 +1,205 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_GetFilesHelper_h
+#define mozilla_dom_GetFilesHelper_h
+
+#include "mozilla/Mutex.h"
+#include "mozilla/RefPtr.h"
+#include "nsCycleCollectionTraversalCallback.h"
+#include "nsTArray.h"
+#include "nsTHashtable.h"
+
+class nsIGlobalObject;
+
+namespace mozilla {
+namespace dom {
+
+class BlobImpl;
+class ContentParent;
+class File;
+class GetFilesHelperParent;
+class OwningFileOrDirectory;
+class Promise;
+
+class GetFilesCallback
+{
+public:
+  NS_INLINE_DECL_REFCOUNTING(GetFilesCallback);
+
+  virtual void
+  Callback(nsresult aStatus, const Sequence<RefPtr<File>>& aFiles) = 0;
+
+protected:
+  virtual ~GetFilesCallback() {}
+};
+
+class GetFilesHelperBase
+{
+protected:
+  explicit GetFilesHelperBase(bool aRecursiveFlag)
+    : mRecursiveFlag(aRecursiveFlag)
+  {}
+
+  virtual ~GetFilesHelperBase() {}
+
+  virtual bool
+  IsCanceled()
+  {
+    return false;
+  }
+
+  nsresult
+  ExploreDirectory(const nsAString& aDOMPath, nsIFile* aFile);
+
+  nsresult
+  AddExploredDirectory(nsIFile* aDirectory);
+
+  bool
+  ShouldFollowSymLink(nsIFile* aDirectory);
+
+  bool mRecursiveFlag;
+
+  // We populate this array in the I/O thread with the BlobImpl.
+  FallibleTArray<RefPtr<BlobImpl>> mTargetBlobImplArray;
+  nsTHashtable<nsCStringHashKey> mExploredDirectories;
+};
+
+// Retrieving the list of files can be very time/IO consuming. We use this
+// helper class to do it just once.
+class GetFilesHelper : public Runnable
+                     , public GetFilesHelperBase
+{
+  friend class GetFilesHelperParent;
+
+public:
+  static already_AddRefed<GetFilesHelper>
+  Create(nsIGlobalObject* aGlobal,
+         const nsTArray<OwningFileOrDirectory>& aFilesOrDirectory,
+         bool aRecursiveFlag, ErrorResult& aRv);
+
+  void
+  AddPromise(Promise* aPromise);
+
+  void
+  AddCallback(GetFilesCallback* aCallback);
+
+  // CC methods
+  void Unlink();
+  void Traverse(nsCycleCollectionTraversalCallback &cb);
+
+protected:
+  GetFilesHelper(nsIGlobalObject* aGlobal, bool aRecursiveFlag);
+
+  virtual ~GetFilesHelper();
+
+  void
+  SetDirectoryPath(const nsAString& aDirectoryPath)
+  {
+    mDirectoryPath = aDirectoryPath;
+  }
+
+  virtual bool
+  IsCanceled() override
+  {
+    MutexAutoLock lock(mMutex);
+    return mCanceled;
+  }
+
+  virtual void
+  Work(ErrorResult& aRv);
+
+  virtual void
+  Cancel() {};
+
+  NS_IMETHOD
+  Run() override;
+
+  void
+  RunIO();
+
+  void
+  RunMainThread();
+
+  void
+  OperationCompleted();
+
+  void
+  ResolveOrRejectPromise(Promise* aPromise);
+
+  void
+  RunCallback(GetFilesCallback* aCallback);
+
+  nsCOMPtr<nsIGlobalObject> mGlobal;
+
+  bool mListingCompleted;
+  nsString mDirectoryPath;
+
+  // This is the real File sequence that we expose via Promises.
+  Sequence<RefPtr<File>> mFiles;
+
+  // Error code to propagate.
+  nsresult mErrorResult;
+
+  nsTArray<RefPtr<Promise>> mPromises;
+  nsTArray<RefPtr<GetFilesCallback>> mCallbacks;
+
+  Mutex mMutex;
+
+  // This variable is protected by mutex.
+  bool mCanceled;
+};
+
+class GetFilesHelperChild final : public GetFilesHelper
+{
+public:
+  GetFilesHelperChild(nsIGlobalObject* aGlobal, bool aRecursiveFlag)
+    : GetFilesHelper(aGlobal, aRecursiveFlag)
+    , mPendingOperation(false)
+  {}
+
+  virtual void
+  Work(ErrorResult& aRv) override;
+
+  virtual void
+  Cancel() override;
+
+  bool
+  AppendBlobImpl(BlobImpl* aBlobImpl);
+
+  void
+  Finished(nsresult aResult);
+
+private:
+  nsID mUUID;
+  bool mPendingOperation;
+};
+
+class GetFilesHelperParentCallback;
+
+class GetFilesHelperParent final : public GetFilesHelper
+{
+  friend class GetFilesHelperParentCallback;
+
+public:
+  static already_AddRefed<GetFilesHelperParent>
+  Create(const nsID& aUUID, const nsAString& aDirectoryPath,
+         bool aRecursiveFlag, ContentParent* aContentParent, ErrorResult& aRv);
+
+private:
+  GetFilesHelperParent(const nsID& aUUID, ContentParent* aContentParent,
+                       bool aRecursiveFlag);
+
+  ~GetFilesHelperParent();
+
+  RefPtr<ContentParent> mContentParent;
+  nsID mUUID;
+};
+
+} // dom namespace
+} // mozilla namespace
+
+#endif // mozilla_dom_GetFilesHelper_h
diff --git a/dom/filesystem/GetFilesTask.cpp b/dom/filesystem/GetFilesTask.cpp
new file mode 100644
index 000000000..6682fb7d3
--- /dev/null
+++ b/dom/filesystem/GetFilesTask.cpp
@@ -0,0 +1,263 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GetFilesTask.h"
+
+#include "HTMLSplitOnSpacesTokenizer.h"
+#include "js/Value.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/dom/FileSystemBase.h"
+#include "mozilla/dom/FileSystemUtils.h"
+#include "mozilla/dom/PFileSystemParams.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/ipc/BlobChild.h"
+#include "mozilla/dom/ipc/BlobParent.h"
+#include "nsIFile.h"
+#include "nsStringGlue.h"
+
+namespace mozilla {
+namespace dom {
+
+/**
+ * GetFilesTaskChild
+ */
+
+/* static */ already_AddRefed<GetFilesTaskChild>
+GetFilesTaskChild::Create(FileSystemBase* aFileSystem,
+                          Directory* aDirectory,
+                          nsIFile* aTargetPath,
+                          bool aRecursiveFlag,
+                          ErrorResult& aRv)
+{
+  MOZ_ASSERT(aFileSystem);
+  MOZ_ASSERT(aDirectory);
+  aFileSystem->AssertIsOnOwningThread();
+
+  nsCOMPtr<nsIGlobalObject> globalObject =
+    do_QueryInterface(aFileSystem->GetParentObject());
+  if (NS_WARN_IF(!globalObject)) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+
+  RefPtr<GetFilesTaskChild> task =
+    new GetFilesTaskChild(aFileSystem, aDirectory, aTargetPath,
+                          aRecursiveFlag);
+
+  // aTargetPath can be null. In this case SetError will be called.
+
+  task->mPromise = Promise::Create(globalObject, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  return task.forget();
+}
+
+GetFilesTaskChild::GetFilesTaskChild(FileSystemBase* aFileSystem,
+                                     Directory* aDirectory,
+                                     nsIFile* aTargetPath,
+                                     bool aRecursiveFlag)
+  : FileSystemTaskChildBase(aFileSystem)
+  , mDirectory(aDirectory)
+  , mTargetPath(aTargetPath)
+  , mRecursiveFlag(aRecursiveFlag)
+{
+  MOZ_ASSERT(aFileSystem);
+  MOZ_ASSERT(aDirectory);
+  aFileSystem->AssertIsOnOwningThread();
+}
+
+GetFilesTaskChild::~GetFilesTaskChild()
+{
+  mFileSystem->AssertIsOnOwningThread();
+}
+
+already_AddRefed<Promise>
+GetFilesTaskChild::GetPromise()
+{
+  mFileSystem->AssertIsOnOwningThread();
+  return RefPtr<Promise>(mPromise).forget();
+}
+
+FileSystemParams
+GetFilesTaskChild::GetRequestParams(const nsString& aSerializedDOMPath,
+                                    ErrorResult& aRv) const
+{
+  mFileSystem->AssertIsOnOwningThread();
+
+  nsAutoString path;
+  aRv = mTargetPath->GetPath(path);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return FileSystemGetFilesParams();
+  }
+
+  nsAutoString domPath;
+  mDirectory->GetPath(domPath, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return FileSystemGetFilesParams();
+  }
+
+  return FileSystemGetFilesParams(aSerializedDOMPath, path, domPath,
+                                  mRecursiveFlag);
+}
+
+void
+GetFilesTaskChild::SetSuccessRequestResult(const FileSystemResponseValue& aValue,
+                                           ErrorResult& aRv)
+{
+  mFileSystem->AssertIsOnOwningThread();
+  MOZ_ASSERT(aValue.type() ==
+               FileSystemResponseValue::TFileSystemFilesResponse);
+
+  FileSystemFilesResponse r = aValue;
+
+  if (!mTargetData.SetLength(r.data().Length(), mozilla::fallible_t())) {
+    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+    return;
+  }
+
+  for (uint32_t i = 0; i < r.data().Length(); ++i) {
+    const FileSystemFileResponse& data = r.data()[i];
+    RefPtr<BlobImpl> blobImpl =
+      static_cast<BlobChild*>(data.blobChild())->GetBlobImpl();
+    MOZ_ASSERT(blobImpl);
+
+    mTargetData[i] = File::Create(mFileSystem->GetParentObject(), blobImpl);
+  }
+}
+
+void
+GetFilesTaskChild::HandlerCallback()
+{
+  mFileSystem->AssertIsOnOwningThread();
+  if (mFileSystem->IsShutdown()) {
+    mPromise = nullptr;
+    return;
+  }
+
+  if (HasError()) {
+    mPromise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR);
+    mPromise = nullptr;
+    return;
+  }
+
+  mPromise->MaybeResolve(mTargetData);
+  mPromise = nullptr;
+}
+
+/**
+ * GetFilesTaskParent
+ */
+
+/* static */ already_AddRefed<GetFilesTaskParent>
+GetFilesTaskParent::Create(FileSystemBase* aFileSystem,
+                           const FileSystemGetFilesParams& aParam,
+                           FileSystemRequestParent* aParent,
+                           ErrorResult& aRv)
+{
+  MOZ_ASSERT(XRE_IsParentProcess(), "Only call from parent process!");
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aFileSystem);
+
+  RefPtr<GetFilesTaskParent> task =
+    new GetFilesTaskParent(aFileSystem, aParam, aParent);
+
+  aRv = NS_NewLocalFile(aParam.realPath(), true,
+                        getter_AddRefs(task->mTargetPath));
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
+  return task.forget();
+}
+
+GetFilesTaskParent::GetFilesTaskParent(FileSystemBase* aFileSystem,
+                                       const FileSystemGetFilesParams& aParam,
+                                       FileSystemRequestParent* aParent)
+  : FileSystemTaskParentBase(aFileSystem, aParam, aParent)
+  , GetFilesHelperBase(aParam.recursiveFlag())
+  , mDirectoryDOMPath(aParam.domPath())
+{
+  MOZ_ASSERT(XRE_IsParentProcess(), "Only call from parent process!");
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aFileSystem);
+}
+
+FileSystemResponseValue
+GetFilesTaskParent::GetSuccessRequestResult(ErrorResult& aRv) const
+{
+  AssertIsOnBackgroundThread();
+
+  InfallibleTArray<PBlobParent*> blobs;
+
+  FallibleTArray<FileSystemFileResponse> inputs;
+  if (!inputs.SetLength(mTargetBlobImplArray.Length(), mozilla::fallible_t())) {
+    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+    FileSystemFilesResponse response;
+    return response;
+  }
+
+  for (unsigned i = 0; i < mTargetBlobImplArray.Length(); i++) {
+    BlobParent* blobParent =
+      BlobParent::GetOrCreate(mRequestParent->Manager(),
+                              mTargetBlobImplArray[i]);
+    inputs[i] = FileSystemFileResponse(blobParent, nullptr);
+  }
+
+  FileSystemFilesResponse response;
+  response.data().SwapElements(inputs);
+  return response;
+}
+
+nsresult
+GetFilesTaskParent::IOWork()
+{
+  MOZ_ASSERT(XRE_IsParentProcess(),
+             "Only call from parent process!");
+  MOZ_ASSERT(!NS_IsMainThread(), "Only call on I/O thread!");
+
+  if (mFileSystem->IsShutdown()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  bool exists;
+  nsresult rv = mTargetPath->Exists(&exists);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (!exists) {
+    return NS_OK;
+  }
+
+  bool isDir;
+  rv = mTargetPath->IsDirectory(&isDir);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  if (!isDir) {
+    return NS_ERROR_DOM_FILESYSTEM_TYPE_MISMATCH_ERR;
+  }
+
+  // Get isDirectory.
+  rv = ExploreDirectory(mDirectoryDOMPath, mTargetPath);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+nsresult
+GetFilesTaskParent::GetTargetPath(nsAString& aPath) const
+{
+  return mTargetPath->GetPath(aPath);
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/filesystem/GetFilesTask.h b/dom/filesystem/GetFilesTask.h
new file mode 100644
index 000000000..be08a5d18
--- /dev/null
+++ b/dom/filesystem/GetFilesTask.h
@@ -0,0 +1,95 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_GetFilesTask_h
+#define mozilla_dom_GetFilesTask_h
+
+#include "mozilla/dom/Directory.h"
+#include "mozilla/dom/FileSystemTaskBase.h"
+#include "mozilla/dom/GetFilesHelper.h"
+#include "mozilla/ErrorResult.h"
+
+namespace mozilla {
+namespace dom {
+
+class BlobImpl;
+class FileSystemGetFilesParams;
+
+class GetFilesTaskChild final : public FileSystemTaskChildBase
+{
+public:
+  static already_AddRefed<GetFilesTaskChild>
+  Create(FileSystemBase* aFileSystem,
+         Directory* aDirectory,
+         nsIFile* aTargetPath,
+         bool aRecursiveFlag,
+         ErrorResult& aRv);
+
+  virtual
+  ~GetFilesTaskChild();
+
+  already_AddRefed<Promise>
+  GetPromise();
+
+private:
+  // If aDirectoryOnly is set, we should ensure that the target is a directory.
+  GetFilesTaskChild(FileSystemBase* aFileSystem,
+                    Directory* aDirectory,
+                    nsIFile* aTargetPath,
+                    bool aRecursiveFlag);
+
+  virtual FileSystemParams
+  GetRequestParams(const nsString& aSerializedDOMPath,
+                   ErrorResult& aRv) const override;
+
+  virtual void
+  SetSuccessRequestResult(const FileSystemResponseValue& aValue,
+                          ErrorResult& aRv) override;
+
+  virtual void
+  HandlerCallback() override;
+
+  RefPtr<Promise> mPromise;
+  RefPtr<Directory> mDirectory;
+  nsCOMPtr<nsIFile> mTargetPath;
+  bool mRecursiveFlag;
+
+  // We store the fullpath and the dom path of Files.
+  FallibleTArray<RefPtr<File>> mTargetData;
+};
+
+class GetFilesTaskParent final : public FileSystemTaskParentBase
+                               , public GetFilesHelperBase
+{
+public:
+  static already_AddRefed<GetFilesTaskParent>
+  Create(FileSystemBase* aFileSystem,
+         const FileSystemGetFilesParams& aParam,
+         FileSystemRequestParent* aParent,
+         ErrorResult& aRv);
+
+  nsresult
+  GetTargetPath(nsAString& aPath) const override;
+
+private:
+  GetFilesTaskParent(FileSystemBase* aFileSystem,
+                     const FileSystemGetFilesParams& aParam,
+                     FileSystemRequestParent* aParent);
+
+  virtual FileSystemResponseValue
+  GetSuccessRequestResult(ErrorResult& aRv) const override;
+
+  virtual nsresult
+  IOWork() override;
+
+  nsString mDirectoryDOMPath;
+  nsCOMPtr<nsIFile> mTargetPath;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_GetFilesTask_h
diff --git a/dom/filesystem/OSFileSystem.cpp b/dom/filesystem/OSFileSystem.cpp
new file mode 100644
index 000000000..1e9a5ddbd
--- /dev/null
+++ b/dom/filesystem/OSFileSystem.cpp
@@ -0,0 +1,113 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/OSFileSystem.h"
+
+#include "mozilla/dom/Directory.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/dom/FileSystemUtils.h"
+#include "nsIGlobalObject.h"
+#include "nsCOMPtr.h"
+#include "nsDebug.h"
+#include "nsIFile.h"
+
+namespace mozilla {
+namespace dom {
+
+OSFileSystem::OSFileSystem(const nsAString& aRootDir)
+{
+  mLocalRootPath = aRootDir;
+}
+
+already_AddRefed<FileSystemBase>
+OSFileSystem::Clone()
+{
+  AssertIsOnOwningThread();
+
+  RefPtr<OSFileSystem> fs = new OSFileSystem(mLocalRootPath);
+  if (mParent) {
+    fs->Init(mParent);
+  }
+
+  return fs.forget();
+}
+
+void
+OSFileSystem::Init(nsISupports* aParent)
+{
+  AssertIsOnOwningThread();
+  MOZ_ASSERT(!mParent, "No duple Init() calls");
+  MOZ_ASSERT(aParent);
+
+  mParent = aParent;
+
+#ifdef DEBUG
+  nsCOMPtr<nsIGlobalObject> obj = do_QueryInterface(aParent);
+  MOZ_ASSERT(obj);
+#endif
+}
+
+nsISupports*
+OSFileSystem::GetParentObject() const
+{
+  AssertIsOnOwningThread();
+  return mParent;
+}
+
+bool
+OSFileSystem::IsSafeFile(nsIFile* aFile) const
+{
+  // The concept of "safe files" is specific to the Device Storage API where
+  // files are only "safe" if they're of a type that is appropriate for the
+  // area of device storage that is being used.
+  MOZ_CRASH("Don't use OSFileSystem with the Device Storage API");
+  return true;
+}
+
+bool
+OSFileSystem::IsSafeDirectory(Directory* aDir) const
+{
+  // The concept of "safe directory" is specific to the Device Storage API
+  // where a directory is only "safe" if it belongs to the area of device
+  // storage that it is being used with.
+  MOZ_CRASH("Don't use OSFileSystem with the Device Storage API");
+  return true;
+}
+
+void
+OSFileSystem::Unlink()
+{
+  AssertIsOnOwningThread();
+  mParent = nullptr;
+}
+
+void
+OSFileSystem::Traverse(nsCycleCollectionTraversalCallback &cb)
+{
+  AssertIsOnOwningThread();
+
+  OSFileSystem* tmp = this;
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParent);
+}
+
+void
+OSFileSystem::SerializeDOMPath(nsAString& aOutput) const
+{
+  AssertIsOnOwningThread();
+  aOutput = mLocalRootPath;
+}
+
+/**
+ * OSFileSystemParent
+ */
+
+OSFileSystemParent::OSFileSystemParent(const nsAString& aRootDir)
+{
+  mLocalRootPath = aRootDir;
+}
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/filesystem/OSFileSystem.h b/dom/filesystem/OSFileSystem.h
new file mode 100644
index 000000000..165f6b99a
--- /dev/null
+++ b/dom/filesystem/OSFileSystem.h
@@ -0,0 +1,132 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_OSFileSystem_h
+#define mozilla_dom_OSFileSystem_h
+
+#include "mozilla/dom/FileSystemBase.h"
+
+namespace mozilla {
+namespace dom {
+
+class OSFileSystem final : public FileSystemBase
+{
+public:
+  explicit OSFileSystem(const nsAString& aRootDir);
+
+  void
+  Init(nsISupports* aParent);
+
+  // Overrides FileSystemBase
+
+  virtual already_AddRefed<FileSystemBase>
+  Clone() override;
+
+  virtual bool
+  ShouldCreateDirectory() override
+  {
+    MOZ_CRASH("This should not be called.");
+    // Because OSFileSystem should not be used when the creation of directories
+    // is needed. For that we have OSFileSystemParent.
+    return false;
+  }
+
+  virtual nsISupports*
+  GetParentObject() const override;
+
+  virtual bool
+  IsSafeFile(nsIFile* aFile) const override;
+
+  virtual bool
+  IsSafeDirectory(Directory* aDir) const override;
+
+  virtual void
+  SerializeDOMPath(nsAString& aOutput) const override;
+
+  virtual bool
+  ClonableToDifferentThreadOrProcess() const override { return true; }
+
+  // CC methods
+  virtual void Unlink() override;
+  virtual void Traverse(nsCycleCollectionTraversalCallback &cb) override;
+
+private:
+  virtual ~OSFileSystem() {}
+
+  nsCOMPtr<nsISupports> mParent;
+};
+
+class OSFileSystemParent final : public FileSystemBase
+{
+public:
+  explicit OSFileSystemParent(const nsAString& aRootDir);
+
+  // Overrides FileSystemBase
+
+  virtual already_AddRefed<FileSystemBase>
+  Clone() override
+  {
+    MOZ_CRASH("This should not be called on the PBackground thread.");
+    return nullptr;
+  }
+
+  virtual bool
+  ShouldCreateDirectory() override { return false; }
+
+  virtual nsISupports*
+  GetParentObject() const override
+  {
+    MOZ_CRASH("This should not be called on the PBackground thread.");
+    return nullptr;
+  }
+
+  virtual void
+  GetDirectoryName(nsIFile* aFile, nsAString& aRetval,
+                   ErrorResult& aRv) const override
+  {
+    MOZ_CRASH("This should not be called on the PBackground thread.");
+  }
+
+  virtual bool
+  IsSafeFile(nsIFile* aFile) const override
+  {
+    return true;
+  }
+
+  virtual bool
+  IsSafeDirectory(Directory* aDir) const override
+  {
+    MOZ_CRASH("This should not be called on the PBackground thread.");
+    return true;
+  }
+
+  virtual void
+  SerializeDOMPath(nsAString& aOutput) const override
+  {
+    MOZ_CRASH("This should not be called on the PBackground thread.");
+  }
+
+  // CC methods
+  virtual void
+  Unlink() override
+  {
+    MOZ_CRASH("This should not be called on the PBackground thread.");
+  }
+
+  virtual void
+  Traverse(nsCycleCollectionTraversalCallback &cb) override
+  {
+    MOZ_CRASH("This should not be called on the PBackground thread.");
+  }
+
+private:
+  virtual ~OSFileSystemParent() {}
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_OSFileSystem_h
diff --git a/dom/filesystem/PFileSystemParams.ipdlh b/dom/filesystem/PFileSystemParams.ipdlh
new file mode 100644
index 000000000..08929b6f2
--- /dev/null
+++ b/dom/filesystem/PFileSystemParams.ipdlh
@@ -0,0 +1,50 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+include protocol PBlob;
+
+namespace mozilla {
+namespace dom {
+
+struct FileSystemGetDirectoryListingParams
+{
+  nsString filesystem;
+  nsString realPath;
+  nsString domPath;
+
+  // 'filters' could be an array rather than a semicolon separated string
+  // (we'd then use InfallibleTArray<nsString> internally), but that is
+  // wasteful.  E10s requires us to pass the filters over as a string anyway,
+  // so avoiding using an array avoids serialization on the side passing the
+  // filters.  Since an nsString can share its buffer when copied,
+  // using that instead of InfallibleTArray<nsString> makes copying the filters
+  // around in any given process a bit more efficient too, since copying a
+  // single nsString is cheaper than copying InfallibleTArray member data and
+  // each nsString that it contains.
+  nsString filters;
+};
+
+struct FileSystemGetFilesParams
+{
+  nsString filesystem;
+  nsString realPath;
+  nsString domPath;
+  bool recursiveFlag;
+};
+
+struct FileSystemGetFileOrDirectoryParams
+{
+  nsString filesystem;
+  nsString realPath;
+};
+
+union FileSystemParams
+{
+  FileSystemGetDirectoryListingParams;
+  FileSystemGetFilesParams;
+  FileSystemGetFileOrDirectoryParams;
+};
+
+} // dom namespace
+} // mozilla namespace
diff --git a/dom/filesystem/PFileSystemRequest.ipdl b/dom/filesystem/PFileSystemRequest.ipdl
new file mode 100644
index 000000000..49803a770
--- /dev/null
+++ b/dom/filesystem/PFileSystemRequest.ipdl
@@ -0,0 +1,73 @@
+/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+include protocol PBackground;
+include protocol PBlob;
+
+namespace mozilla {
+namespace dom {
+
+struct FileSystemFileResponse
+{
+  PBlob blob;
+};
+
+struct FileSystemDirectoryResponse
+{
+  nsString realPath;
+};
+
+struct FileSystemDirectoryListingResponseFile
+{
+  PBlob blob;
+};
+
+struct FileSystemDirectoryListingResponseDirectory
+{
+  // This is the full real path for the directory that we are sending via IPC.
+  nsString directoryRealPath;
+};
+
+union FileSystemDirectoryListingResponseData
+{
+  FileSystemDirectoryListingResponseFile;
+  FileSystemDirectoryListingResponseDirectory;
+};
+
+struct FileSystemDirectoryListingResponse
+{
+  FileSystemDirectoryListingResponseData[] data;
+};
+
+struct FileSystemFilesResponse
+{
+  FileSystemFileResponse[] data;
+};
+
+struct FileSystemErrorResponse
+{
+  nsresult error;
+};
+
+union FileSystemResponseValue
+{
+  FileSystemDirectoryResponse;
+  FileSystemDirectoryListingResponse;
+  FileSystemFileResponse;
+  FileSystemFilesResponse;
+  FileSystemErrorResponse;
+};
+
+protocol PFileSystemRequest
+{
+  manager PBackground;
+
+child:
+  async __delete__(FileSystemResponseValue response);
+};
+
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/filesystem/compat/CallbackRunnables.cpp b/dom/filesystem/compat/CallbackRunnables.cpp
new file mode 100644
index 000000000..efd14b03e
--- /dev/null
+++ b/dom/filesystem/compat/CallbackRunnables.cpp
@@ -0,0 +1,306 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CallbackRunnables.h"
+#include "mozilla/dom/Directory.h"
+#include "mozilla/dom/DirectoryBinding.h"
+#include "mozilla/dom/DOMException.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/dom/FileBinding.h"
+#include "mozilla/dom/FileSystemDirectoryReaderBinding.h"
+#include "mozilla/dom/FileSystemFileEntry.h"
+#include "mozilla/dom/FileSystemUtils.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/Unused.h"
+#include "nsIGlobalObject.h"
+#include "nsIFile.h"
+#include "nsPIDOMWindow.h"
+
+#include "../GetFileOrDirectoryTask.h"
+
+namespace mozilla {
+namespace dom {
+
+EntryCallbackRunnable::EntryCallbackRunnable(FileSystemEntryCallback* aCallback,
+                                             FileSystemEntry* aEntry)
+  : mCallback(aCallback)
+  , mEntry(aEntry)
+{
+  MOZ_ASSERT(aCallback);
+  MOZ_ASSERT(aEntry);
+}
+
+NS_IMETHODIMP
+EntryCallbackRunnable::Run()
+{
+  mCallback->HandleEvent(*mEntry);
+  return NS_OK;
+}
+
+ErrorCallbackRunnable::ErrorCallbackRunnable(nsIGlobalObject* aGlobalObject,
+                                             ErrorCallback* aCallback,
+                                             nsresult aError)
+  : mGlobal(aGlobalObject)
+  , mCallback(aCallback)
+  , mError(aError)
+{
+  MOZ_ASSERT(aGlobalObject);
+  MOZ_ASSERT(aCallback);
+  MOZ_ASSERT(NS_FAILED(aError));
+}
+
+NS_IMETHODIMP
+ErrorCallbackRunnable::Run()
+{
+  nsCOMPtr<nsPIDOMWindowInner> window = do_QueryInterface(mGlobal);
+  if (NS_WARN_IF(!window)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  RefPtr<DOMException> exception = DOMException::Create(mError);
+  mCallback->HandleEvent(*exception);
+  return NS_OK;
+}
+
+EmptyEntriesCallbackRunnable::EmptyEntriesCallbackRunnable(FileSystemEntriesCallback* aCallback)
+  : mCallback(aCallback)
+{
+  MOZ_ASSERT(aCallback);
+}
+
+NS_IMETHODIMP
+EmptyEntriesCallbackRunnable::Run()
+{
+  Sequence<OwningNonNull<FileSystemEntry>> sequence;
+  mCallback->HandleEvent(sequence);
+  return NS_OK;
+}
+
+GetEntryHelper::GetEntryHelper(FileSystemDirectoryEntry* aParentEntry,
+                               Directory* aDirectory,
+                               nsTArray<nsString>& aParts,
+                               FileSystem* aFileSystem,
+                               FileSystemEntryCallback* aSuccessCallback,
+                               ErrorCallback* aErrorCallback,
+                               FileSystemDirectoryEntry::GetInternalType aType)
+  : mParentEntry(aParentEntry)
+  , mDirectory(aDirectory)
+  , mParts(aParts)
+  , mFileSystem(aFileSystem)
+  , mSuccessCallback(aSuccessCallback)
+  , mErrorCallback(aErrorCallback)
+  , mType(aType)
+{
+  MOZ_ASSERT(aParentEntry);
+  MOZ_ASSERT(aDirectory);
+  MOZ_ASSERT(!aParts.IsEmpty());
+  MOZ_ASSERT(aFileSystem);
+  MOZ_ASSERT(aSuccessCallback || aErrorCallback);
+}
+
+GetEntryHelper::~GetEntryHelper()
+{}
+
+namespace {
+
+nsresult
+DOMPathToRealPath(Directory* aDirectory, const nsAString& aPath,
+                  nsIFile** aFile)
+{
+  nsString relativePath;
+  relativePath = aPath;
+
+  // Trim white spaces.
+  static const char kWhitespace[] = "\b\t\r\n ";
+  relativePath.Trim(kWhitespace);
+
+  nsTArray<nsString> parts;
+  if (!FileSystemUtils::IsValidRelativeDOMPath(relativePath, parts)) {
+    return NS_ERROR_DOM_FILESYSTEM_INVALID_PATH_ERR;
+  }
+
+  nsCOMPtr<nsIFile> file;
+  nsresult rv = aDirectory->GetInternalNsIFile()->Clone(getter_AddRefs(file));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  for (uint32_t i = 0; i < parts.Length(); ++i) {
+    rv = file->AppendRelativePath(parts[i]);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  file.forget(aFile);
+  return NS_OK;
+}
+
+} // anonymous
+
+void
+GetEntryHelper::Run()
+{
+  MOZ_ASSERT(!mParts.IsEmpty());
+
+  nsCOMPtr<nsIFile> realPath;
+  nsresult error = DOMPathToRealPath(mDirectory, mParts[0],
+                                     getter_AddRefs(realPath));
+
+  ErrorResult rv;
+  RefPtr<FileSystemBase> fs = mDirectory->GetFileSystem(rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    rv.SuppressException();
+    Error(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return;
+  }
+
+  RefPtr<GetFileOrDirectoryTaskChild> task =
+    GetFileOrDirectoryTaskChild::Create(fs, realPath, rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    rv.SuppressException();
+    Error(NS_ERROR_DOM_INVALID_STATE_ERR);
+    return;
+  }
+
+  task->SetError(error);
+  task->Start();
+
+  RefPtr<Promise> promise = task->GetPromise();
+
+  mParts.RemoveElementAt(0);
+  promise->AppendNativeHandler(this);
+}
+
+void
+GetEntryHelper::ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue)
+{
+  if(NS_WARN_IF(!aValue.isObject())) {
+    return;
+  }
+
+  JS::Rooted<JSObject*> obj(aCx, &aValue.toObject());
+
+  // This is not the last part of the path.
+  if (!mParts.IsEmpty()) {
+    ContinueRunning(obj);
+    return;
+  }
+
+  CompleteOperation(obj);
+}
+
+void
+GetEntryHelper::CompleteOperation(JSObject* aObj)
+{
+  MOZ_ASSERT(mParts.IsEmpty());
+
+  if (mType == FileSystemDirectoryEntry::eGetFile) {
+    RefPtr<File> file;
+    if (NS_FAILED(UNWRAP_OBJECT(File, aObj, file))) {
+      Error(NS_ERROR_DOM_TYPE_MISMATCH_ERR);
+      return;
+    }
+
+    RefPtr<FileSystemFileEntry> entry =
+      new FileSystemFileEntry(mParentEntry->GetParentObject(), file,
+                              mParentEntry, mFileSystem);
+    mSuccessCallback->HandleEvent(*entry);
+    return;
+  }
+
+  MOZ_ASSERT(mType == FileSystemDirectoryEntry::eGetDirectory);
+
+  RefPtr<Directory> directory;
+  if (NS_FAILED(UNWRAP_OBJECT(Directory, aObj, directory))) {
+    Error(NS_ERROR_DOM_TYPE_MISMATCH_ERR);
+    return;
+  }
+
+  RefPtr<FileSystemDirectoryEntry> entry =
+    new FileSystemDirectoryEntry(mParentEntry->GetParentObject(), directory,
+                                 mParentEntry, mFileSystem);
+  mSuccessCallback->HandleEvent(*entry);
+}
+
+void
+GetEntryHelper::ContinueRunning(JSObject* aObj)
+{
+  MOZ_ASSERT(!mParts.IsEmpty());
+
+  RefPtr<Directory> directory;
+  if (NS_FAILED(UNWRAP_OBJECT(Directory, aObj, directory))) {
+    Error(NS_ERROR_DOM_TYPE_MISMATCH_ERR);
+    return;
+  }
+
+  RefPtr<FileSystemDirectoryEntry> entry =
+    new FileSystemDirectoryEntry(mParentEntry->GetParentObject(), directory,
+                                 mParentEntry, mFileSystem);
+
+  // Update the internal values.
+  mParentEntry = entry;
+  mDirectory = directory;
+
+  Run();
+}
+
+void
+GetEntryHelper::RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue)
+{
+  Error(NS_ERROR_DOM_NOT_FOUND_ERR);
+}
+
+void
+GetEntryHelper::Error(nsresult aError)
+{
+  MOZ_ASSERT(NS_FAILED(aError));
+
+  if (mErrorCallback) {
+    RefPtr<ErrorCallbackRunnable> runnable =
+      new ErrorCallbackRunnable(mParentEntry->GetParentObject(),
+                                mErrorCallback, aError);
+    DebugOnly<nsresult> rv = NS_DispatchToMainThread(runnable);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_DispatchToMainThread failed");
+  }
+}
+
+NS_IMPL_ISUPPORTS0(GetEntryHelper);
+
+/* static */ void
+FileSystemEntryCallbackHelper::Call(const Optional<OwningNonNull<FileSystemEntryCallback>>& aEntryCallback,
+                                    FileSystemEntry* aEntry)
+{
+  MOZ_ASSERT(aEntry);
+
+  if (aEntryCallback.WasPassed()) {
+    RefPtr<EntryCallbackRunnable> runnable =
+      new EntryCallbackRunnable(&aEntryCallback.Value(), aEntry);
+
+    DebugOnly<nsresult> rv = NS_DispatchToMainThread(runnable);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_DispatchToMainThread failed");
+  }
+}
+
+/* static */ void
+ErrorCallbackHelper::Call(nsIGlobalObject* aGlobal,
+                          const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback,
+                          nsresult aError)
+{
+  MOZ_ASSERT(aGlobal);
+  MOZ_ASSERT(NS_FAILED(aError));
+
+  if (aErrorCallback.WasPassed()) {
+    RefPtr<ErrorCallbackRunnable> runnable =
+      new ErrorCallbackRunnable(aGlobal, &aErrorCallback.Value(), aError);
+    DebugOnly<nsresult> rv = NS_DispatchToMainThread(runnable);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_DispatchToMainThread failed");
+  }
+}
+
+} // dom namespace
+} // mozilla namespace
+
diff --git a/dom/filesystem/compat/CallbackRunnables.h b/dom/filesystem/compat/CallbackRunnables.h
new file mode 100644
index 000000000..3ff77f1a9
--- /dev/null
+++ b/dom/filesystem/compat/CallbackRunnables.h
@@ -0,0 +1,128 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_ErrorCallbackRunnable_h
+#define mozilla_dom_ErrorCallbackRunnable_h
+
+#include "FileSystemDirectoryEntry.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/PromiseNativeHandler.h"
+
+class nsIGlobalObject;
+
+namespace mozilla {
+namespace dom {
+
+class FileSystemEntriesCallback;
+
+class EntryCallbackRunnable final : public Runnable
+{
+public:
+  EntryCallbackRunnable(FileSystemEntryCallback* aCallback,
+                        FileSystemEntry* aEntry);
+
+  NS_IMETHOD
+  Run() override;
+
+private:
+  RefPtr<FileSystemEntryCallback> mCallback;
+  RefPtr<FileSystemEntry> mEntry;
+};
+
+class ErrorCallbackRunnable final : public Runnable
+{
+public:
+  ErrorCallbackRunnable(nsIGlobalObject* aGlobalObject,
+                        ErrorCallback* aCallback,
+                        nsresult aError);
+
+  NS_IMETHOD
+  Run() override;
+
+private:
+  nsCOMPtr<nsIGlobalObject> mGlobal;
+  RefPtr<ErrorCallback> mCallback;
+  nsresult mError;
+};
+
+class EmptyEntriesCallbackRunnable final : public Runnable
+{
+public:
+  explicit EmptyEntriesCallbackRunnable(FileSystemEntriesCallback* aCallback);
+
+  NS_IMETHOD
+  Run() override;
+
+private:
+  RefPtr<FileSystemEntriesCallback> mCallback;
+};
+
+class GetEntryHelper final : public PromiseNativeHandler
+{
+public:
+  NS_DECL_ISUPPORTS
+
+  GetEntryHelper(FileSystemDirectoryEntry* aParentEntry,
+                 Directory* aDirectory,
+                 nsTArray<nsString>& aParts,
+                 FileSystem* aFileSystem,
+                 FileSystemEntryCallback* aSuccessCallback,
+                 ErrorCallback* aErrorCallback,
+                 FileSystemDirectoryEntry::GetInternalType aType);
+
+  void
+  Run();
+
+  virtual void
+  ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override;
+
+  virtual void
+  RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override;
+
+private:
+  ~GetEntryHelper();
+
+  void
+  Error(nsresult aError);
+
+  void
+  ContinueRunning(JSObject* aObj);
+
+  void
+  CompleteOperation(JSObject* aObj);
+
+  RefPtr<FileSystemDirectoryEntry> mParentEntry;
+  RefPtr<Directory> mDirectory;
+  nsTArray<nsString> mParts;
+  RefPtr<FileSystem> mFileSystem;
+
+  RefPtr<FileSystemEntryCallback> mSuccessCallback;
+  RefPtr<ErrorCallback> mErrorCallback;
+
+  FileSystemDirectoryEntry::GetInternalType mType;
+};
+
+class FileSystemEntryCallbackHelper
+{
+public:
+  static void
+  Call(const Optional<OwningNonNull<FileSystemEntryCallback>>& aEntryCallback,
+       FileSystemEntry* aEntry);
+};
+
+class ErrorCallbackHelper
+{
+public:
+  static void
+  Call(nsIGlobalObject* aGlobal,
+       const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback,
+       nsresult aError);
+};
+
+} // dom namespace
+} // mozilla namespace
+
+#endif // mozilla_dom_CallbackRunnables_h
diff --git a/dom/filesystem/compat/FileSystem.cpp b/dom/filesystem/compat/FileSystem.cpp
new file mode 100644
index 000000000..b45980fc6
--- /dev/null
+++ b/dom/filesystem/compat/FileSystem.cpp
@@ -0,0 +1,75 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FileSystem.h"
+#include "FileSystemRootDirectoryEntry.h"
+#include "mozilla/dom/FileSystemBinding.h"
+#include "nsContentUtils.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(FileSystem, mParent, mRoot)
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(FileSystem)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(FileSystem)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(FileSystem)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+/* static */ already_AddRefed<FileSystem>
+FileSystem::Create(nsIGlobalObject* aGlobalObject)
+
+{
+  MOZ_ASSERT(aGlobalObject);
+
+
+  nsID id;
+  nsresult rv = nsContentUtils::GenerateUUIDInPlace(id);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+
+  char chars[NSID_LENGTH];
+  id.ToProvidedString(chars);
+
+  // Any fileSystem has an unique ID. We use UUID, but our generator produces
+  // UUID in this format '{' + UUID + '}'. We remove them with these +1 and -2.
+  nsAutoCString name(Substring(chars + 1, chars + NSID_LENGTH - 2));
+
+  RefPtr<FileSystem> fs =
+    new FileSystem(aGlobalObject, NS_ConvertUTF8toUTF16(name));
+
+  return fs.forget();
+}
+
+FileSystem::FileSystem(nsIGlobalObject* aGlobal, const nsAString& aName)
+  : mParent(aGlobal)
+  , mName(aName)
+{
+  MOZ_ASSERT(aGlobal);
+}
+
+FileSystem::~FileSystem()
+{}
+
+JSObject*
+FileSystem::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return FileSystemBinding::Wrap(aCx, this, aGivenProto);
+}
+
+void
+FileSystem::CreateRoot(const Sequence<RefPtr<FileSystemEntry>>& aEntries)
+{
+  MOZ_ASSERT(!mRoot);
+  mRoot = new FileSystemRootDirectoryEntry(mParent, aEntries, this);
+}
+
+} // dom namespace
+} // mozilla namespace
diff --git a/dom/filesystem/compat/FileSystem.h b/dom/filesystem/compat/FileSystem.h
new file mode 100644
index 000000000..43ce2ea38
--- /dev/null
+++ b/dom/filesystem/compat/FileSystem.h
@@ -0,0 +1,73 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystem_h
+#define mozilla_dom_FileSystem_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/ErrorResult.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsWrapperCache.h"
+
+class nsIGlobalObject;
+
+namespace mozilla {
+namespace dom {
+
+class FileSystemDirectoryEntry;
+class FileSystemEntry;
+class OwningFileOrDirectory;
+
+class FileSystem final
+  : public nsISupports
+  , public nsWrapperCache
+{
+public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(FileSystem)
+
+  static already_AddRefed<FileSystem>
+  Create(nsIGlobalObject* aGlobalObject);
+
+  nsIGlobalObject*
+  GetParentObject() const
+  {
+    return mParent;
+  }
+
+  virtual JSObject*
+  WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  void
+  GetName(nsAString& aName) const
+  {
+    aName = mName;
+  }
+
+  FileSystemDirectoryEntry*
+  Root() const
+  {
+    return mRoot;
+  }
+
+  void
+  CreateRoot(const Sequence<RefPtr<FileSystemEntry>>& aEntries);
+
+private:
+  explicit FileSystem(nsIGlobalObject* aGlobalObject,
+                      const nsAString& aName);
+  ~FileSystem();
+
+  nsCOMPtr<nsIGlobalObject> mParent;
+  RefPtr<FileSystemDirectoryEntry> mRoot;
+  nsString mName;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileSystem_h
diff --git a/dom/filesystem/compat/FileSystemDirectoryEntry.cpp b/dom/filesystem/compat/FileSystemDirectoryEntry.cpp
new file mode 100644
index 000000000..3157ef654
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemDirectoryEntry.cpp
@@ -0,0 +1,107 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FileSystemDirectoryEntry.h"
+#include "CallbackRunnables.h"
+#include "FileSystemDirectoryReader.h"
+#include "mozilla/dom/Directory.h"
+#include "mozilla/dom/FileSystemDirectoryEntryBinding.h"
+#include "mozilla/dom/FileSystemUtils.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(FileSystemDirectoryEntry, FileSystemEntry,
+                                   mDirectory)
+
+NS_IMPL_ADDREF_INHERITED(FileSystemDirectoryEntry, FileSystemEntry)
+NS_IMPL_RELEASE_INHERITED(FileSystemDirectoryEntry, FileSystemEntry)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(FileSystemDirectoryEntry)
+NS_INTERFACE_MAP_END_INHERITING(FileSystemEntry)
+
+FileSystemDirectoryEntry::FileSystemDirectoryEntry(nsIGlobalObject* aGlobal,
+                                                   Directory* aDirectory,
+                                                   FileSystemDirectoryEntry* aParentEntry,
+                                                   FileSystem* aFileSystem)
+  : FileSystemEntry(aGlobal, aParentEntry, aFileSystem)
+  , mDirectory(aDirectory)
+{
+  MOZ_ASSERT(aGlobal);
+}
+
+FileSystemDirectoryEntry::~FileSystemDirectoryEntry()
+{}
+
+JSObject*
+FileSystemDirectoryEntry::WrapObject(JSContext* aCx,
+                                     JS::Handle<JSObject*> aGivenProto)
+{
+  return FileSystemDirectoryEntryBinding::Wrap(aCx, this, aGivenProto);
+}
+
+void
+FileSystemDirectoryEntry::GetName(nsAString& aName, ErrorResult& aRv) const
+{
+  MOZ_ASSERT(mDirectory);
+  mDirectory->GetName(aName, aRv);
+}
+
+void
+FileSystemDirectoryEntry::GetFullPath(nsAString& aPath, ErrorResult& aRv) const
+{
+  MOZ_ASSERT(mDirectory);
+  mDirectory->GetPath(aPath, aRv);
+}
+
+already_AddRefed<FileSystemDirectoryReader>
+FileSystemDirectoryEntry::CreateReader()
+{
+  MOZ_ASSERT(mDirectory);
+
+  RefPtr<FileSystemDirectoryReader> reader =
+    new FileSystemDirectoryReader(this, Filesystem(), mDirectory);
+  return reader.forget();
+}
+
+void
+FileSystemDirectoryEntry::GetInternal(const nsAString& aPath,
+                                      const FileSystemFlags& aFlag,
+                                      const Optional<OwningNonNull<FileSystemEntryCallback>>& aSuccessCallback,
+                                      const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback,
+                                      GetInternalType aType)
+{
+  MOZ_ASSERT(mDirectory);
+
+  if (!aSuccessCallback.WasPassed() && !aErrorCallback.WasPassed()) {
+    return;
+  }
+
+  if (aFlag.mCreate) {
+    ErrorCallbackHelper::Call(GetParentObject(), aErrorCallback,
+                              NS_ERROR_DOM_SECURITY_ERR);
+    return;
+  }
+
+  nsTArray<nsString> parts;
+  if (!FileSystemUtils::IsValidRelativeDOMPath(aPath, parts)) {
+    ErrorCallbackHelper::Call(GetParentObject(), aErrorCallback,
+                              NS_ERROR_DOM_NOT_FOUND_ERR);
+    return;
+  }
+
+  RefPtr<GetEntryHelper> helper =
+    new GetEntryHelper(this, mDirectory, parts, Filesystem(),
+                       aSuccessCallback.WasPassed()
+                         ? &aSuccessCallback.Value() : nullptr,
+                       aErrorCallback.WasPassed()
+                         ? &aErrorCallback.Value() : nullptr,
+                       aType);
+  helper->Run();
+}
+
+} // dom namespace
+} // mozilla namespace
diff --git a/dom/filesystem/compat/FileSystemDirectoryEntry.h b/dom/filesystem/compat/FileSystemDirectoryEntry.h
new file mode 100644
index 000000000..96dc21831
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemDirectoryEntry.h
@@ -0,0 +1,84 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystemDirectoryEntry_h
+#define mozilla_dom_FileSystemDirectoryEntry_h
+
+#include "mozilla/dom/FileSystemEntry.h"
+
+namespace mozilla {
+namespace dom {
+
+class Directory;
+class FileSystemDirectoryReader;
+
+class FileSystemDirectoryEntry : public FileSystemEntry
+{
+public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(FileSystemDirectoryEntry,
+                                           FileSystemEntry)
+
+  FileSystemDirectoryEntry(nsIGlobalObject* aGlobalObject,
+                           Directory* aDirectory,
+                           FileSystemDirectoryEntry* aParentEntry,
+                           FileSystem* aFileSystem);
+
+  virtual JSObject*
+  WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  virtual bool
+  IsDirectory() const override
+  {
+    return true;
+  }
+
+  virtual void
+  GetName(nsAString& aName, ErrorResult& aRv) const override;
+
+  virtual void
+  GetFullPath(nsAString& aFullPath, ErrorResult& aRv) const override;
+
+  virtual already_AddRefed<FileSystemDirectoryReader>
+  CreateReader();
+
+  void
+  GetFile(const Optional<nsAString>& aPath, const FileSystemFlags& aFlag,
+          const Optional<OwningNonNull<FileSystemEntryCallback>>& aSuccessCallback,
+          const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback)
+  {
+    GetInternal(aPath.WasPassed() ? aPath.Value() : EmptyString(),
+                aFlag, aSuccessCallback, aErrorCallback, eGetFile);
+  }
+
+  void
+  GetDirectory(const Optional<nsAString>& aPath, const FileSystemFlags& aFlag,
+               const Optional<OwningNonNull<FileSystemEntryCallback>>& aSuccessCallback,
+               const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback)
+  {
+    GetInternal(aPath.WasPassed() ? aPath.Value() : EmptyString(),
+                aFlag, aSuccessCallback, aErrorCallback, eGetDirectory);
+  }
+
+  enum GetInternalType { eGetFile, eGetDirectory };
+
+  virtual void
+  GetInternal(const nsAString& aPath, const FileSystemFlags& aFlag,
+              const Optional<OwningNonNull<FileSystemEntryCallback>>& aSuccessCallback,
+              const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback,
+              GetInternalType aType);
+
+protected:
+  virtual ~FileSystemDirectoryEntry();
+
+private:
+  RefPtr<Directory> mDirectory;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileSystemDirectoryEntry_h
diff --git a/dom/filesystem/compat/FileSystemDirectoryReader.cpp b/dom/filesystem/compat/FileSystemDirectoryReader.cpp
new file mode 100644
index 000000000..137437378
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemDirectoryReader.cpp
@@ -0,0 +1,188 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FileSystemDirectoryReader.h"
+#include "CallbackRunnables.h"
+#include "FileSystemFileEntry.h"
+#include "mozilla/dom/FileBinding.h"
+#include "mozilla/dom/Directory.h"
+#include "mozilla/dom/DirectoryBinding.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/PromiseNativeHandler.h"
+
+namespace mozilla {
+namespace dom {
+
+namespace {
+
+class PromiseHandler final : public PromiseNativeHandler
+{
+public:
+  NS_DECL_ISUPPORTS
+
+  PromiseHandler(FileSystemDirectoryEntry* aParentEntry,
+                 FileSystem* aFileSystem,
+                 FileSystemEntriesCallback* aSuccessCallback,
+                 ErrorCallback* aErrorCallback)
+    : mParentEntry(aParentEntry)
+    , mFileSystem(aFileSystem)
+    , mSuccessCallback(aSuccessCallback)
+    , mErrorCallback(aErrorCallback)
+  {
+    MOZ_ASSERT(aParentEntry);
+    MOZ_ASSERT(aFileSystem);
+    MOZ_ASSERT(aSuccessCallback);
+  }
+
+  virtual void
+  ResolvedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override
+  {
+    if(NS_WARN_IF(!aValue.isObject())) {
+      return;
+    }
+
+    JS::Rooted<JSObject*> obj(aCx, &aValue.toObject());
+
+    uint32_t length;
+    if (NS_WARN_IF(!JS_GetArrayLength(aCx, obj, &length))) {
+      return;
+    }
+
+    Sequence<OwningNonNull<FileSystemEntry>> sequence;
+    if (NS_WARN_IF(!sequence.SetLength(length, fallible))) {
+      return;
+    }
+
+    for (uint32_t i = 0; i < length; ++i) {
+      JS::Rooted<JS::Value> value(aCx);
+      if (NS_WARN_IF(!JS_GetElement(aCx, obj, i, &value))) {
+        return;
+      }
+
+      if(NS_WARN_IF(!value.isObject())) {
+        return;
+      }
+
+      JS::Rooted<JSObject*> valueObj(aCx, &value.toObject());
+
+      RefPtr<File> file;
+      if (NS_SUCCEEDED(UNWRAP_OBJECT(File, valueObj, file))) {
+        RefPtr<FileSystemFileEntry> entry =
+          new FileSystemFileEntry(mParentEntry->GetParentObject(), file,
+                                  mParentEntry, mFileSystem);
+        sequence[i] = entry;
+        continue;
+      }
+
+      RefPtr<Directory> directory;
+      if (NS_WARN_IF(NS_FAILED(UNWRAP_OBJECT(Directory, valueObj,
+                                             directory)))) {
+        return;
+      }
+
+      RefPtr<FileSystemDirectoryEntry> entry =
+        new FileSystemDirectoryEntry(mParentEntry->GetParentObject(), directory,
+                                     mParentEntry, mFileSystem);
+      sequence[i] = entry;
+    }
+
+    mSuccessCallback->HandleEvent(sequence);
+  }
+
+  virtual void
+  RejectedCallback(JSContext* aCx, JS::Handle<JS::Value> aValue) override
+  {
+    if (mErrorCallback) {
+      RefPtr<ErrorCallbackRunnable> runnable =
+        new ErrorCallbackRunnable(mParentEntry->GetParentObject(),
+                                  mErrorCallback,
+                                  NS_ERROR_DOM_INVALID_STATE_ERR);
+      DebugOnly<nsresult> rv = NS_DispatchToMainThread(runnable);
+      NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_DispatchToMainThread failed");
+    }
+  }
+
+private:
+  ~PromiseHandler() {}
+
+  RefPtr<FileSystemDirectoryEntry> mParentEntry;
+  RefPtr<FileSystem> mFileSystem;
+  RefPtr<FileSystemEntriesCallback> mSuccessCallback;
+  RefPtr<ErrorCallback> mErrorCallback;
+};
+
+NS_IMPL_ISUPPORTS0(PromiseHandler);
+
+} // anonymous namespace
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(FileSystemDirectoryReader, mParentEntry,
+                                      mDirectory, mFileSystem)
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(FileSystemDirectoryReader)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(FileSystemDirectoryReader)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(FileSystemDirectoryReader)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+FileSystemDirectoryReader::FileSystemDirectoryReader(FileSystemDirectoryEntry* aParentEntry,
+                                                     FileSystem* aFileSystem,
+                                                     Directory* aDirectory)
+  : mParentEntry(aParentEntry)
+  , mFileSystem(aFileSystem)
+  , mDirectory(aDirectory)
+  , mAlreadyRead(false)
+{
+  MOZ_ASSERT(aParentEntry);
+  MOZ_ASSERT(aFileSystem);
+}
+
+FileSystemDirectoryReader::~FileSystemDirectoryReader()
+{}
+
+JSObject*
+FileSystemDirectoryReader::WrapObject(JSContext* aCx,
+                                      JS::Handle<JSObject*> aGivenProto)
+{
+  return FileSystemDirectoryReaderBinding::Wrap(aCx, this, aGivenProto);
+}
+
+void
+FileSystemDirectoryReader::ReadEntries(FileSystemEntriesCallback& aSuccessCallback,
+                                       const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback,
+                                       ErrorResult& aRv)
+{
+  MOZ_ASSERT(mDirectory);
+
+  if (mAlreadyRead) {
+    RefPtr<EmptyEntriesCallbackRunnable> runnable =
+      new EmptyEntriesCallbackRunnable(&aSuccessCallback);
+    aRv = NS_DispatchToMainThread(runnable);
+    NS_WARNING_ASSERTION(!aRv.Failed(), "NS_DispatchToMainThread failed");
+    return;
+  }
+
+  // This object can be used only once.
+  mAlreadyRead = true;
+
+  ErrorResult rv;
+  RefPtr<Promise> promise = mDirectory->GetFilesAndDirectories(rv);
+  if (NS_WARN_IF(rv.Failed())) {
+    ErrorCallbackHelper::Call(GetParentObject(), aErrorCallback,
+                              rv.StealNSResult());
+    return;
+  }
+
+  RefPtr<PromiseHandler> handler =
+    new PromiseHandler(mParentEntry, mFileSystem, &aSuccessCallback,
+                       aErrorCallback.WasPassed()
+                         ? &aErrorCallback.Value() : nullptr);
+  promise->AppendNativeHandler(handler);
+}
+
+} // dom namespace
+} // mozilla namespace
diff --git a/dom/filesystem/compat/FileSystemDirectoryReader.h b/dom/filesystem/compat/FileSystemDirectoryReader.h
new file mode 100644
index 000000000..391a79329
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemDirectoryReader.h
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystemDirectoryReader_h
+#define mozilla_dom_FileSystemDirectoryReader_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/ErrorResult.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/FileSystemDirectoryEntry.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsWrapperCache.h"
+
+namespace mozilla {
+namespace dom {
+
+class Directory;
+class FileSystem;
+class FileSystemEntriesCallback;
+
+class FileSystemDirectoryReader
+  : public nsISupports
+  , public nsWrapperCache
+{
+public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(FileSystemDirectoryReader)
+
+  explicit FileSystemDirectoryReader(FileSystemDirectoryEntry* aDirectoryEntry,
+                                     FileSystem* aFileSystem,
+                                     Directory* aDirectory);
+
+  nsIGlobalObject*
+  GetParentObject() const
+  {
+    return mParentEntry->GetParentObject();
+  }
+
+  virtual JSObject*
+  WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  virtual void
+  ReadEntries(FileSystemEntriesCallback& aSuccessCallback,
+              const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback,
+              ErrorResult& aRv);
+
+protected:
+  virtual ~FileSystemDirectoryReader();
+
+private:
+  RefPtr<FileSystemDirectoryEntry> mParentEntry;
+  RefPtr<FileSystem> mFileSystem;
+  RefPtr<Directory> mDirectory;
+
+  bool mAlreadyRead;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileSystemDirectoryReader_h
diff --git a/dom/filesystem/compat/FileSystemEntry.cpp b/dom/filesystem/compat/FileSystemEntry.cpp
new file mode 100644
index 000000000..638c2c6db
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemEntry.cpp
@@ -0,0 +1,89 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FileSystemEntry.h"
+#include "FileSystemDirectoryEntry.h"
+#include "FileSystemFileEntry.h"
+#include "mozilla/dom/FileSystemEntryBinding.h"
+#include "mozilla/dom/UnionTypes.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(FileSystemEntry, mParent, mParentEntry,
+                                      mFileSystem)
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(FileSystemEntry)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(FileSystemEntry)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(FileSystemEntry)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+/* static */ already_AddRefed<FileSystemEntry>
+FileSystemEntry::Create(nsIGlobalObject* aGlobalObject,
+                        const OwningFileOrDirectory& aFileOrDirectory,
+                        FileSystem* aFileSystem)
+{
+  MOZ_ASSERT(aGlobalObject);
+  MOZ_ASSERT(aFileSystem);
+
+  RefPtr<FileSystemEntry> entry;
+  if (aFileOrDirectory.IsFile()) {
+    entry = new FileSystemFileEntry(aGlobalObject,
+                                    aFileOrDirectory.GetAsFile(),
+                                    nullptr,
+                                    aFileSystem);
+  } else {
+    MOZ_ASSERT(aFileOrDirectory.IsDirectory());
+    entry = new FileSystemDirectoryEntry(aGlobalObject,
+                                         aFileOrDirectory.GetAsDirectory(),
+                                         nullptr,
+                                         aFileSystem);
+  }
+
+  return entry.forget();
+}
+
+FileSystemEntry::FileSystemEntry(nsIGlobalObject* aGlobal,
+                                 FileSystemEntry* aParentEntry,
+                                 FileSystem* aFileSystem)
+  : mParent(aGlobal)
+  , mParentEntry(aParentEntry)
+  , mFileSystem(aFileSystem)
+{
+  MOZ_ASSERT(aGlobal);
+  MOZ_ASSERT(aFileSystem);
+}
+
+FileSystemEntry::~FileSystemEntry()
+{}
+
+JSObject*
+FileSystemEntry::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return FileSystemEntryBinding::Wrap(aCx, this, aGivenProto);
+}
+
+void
+FileSystemEntry::GetParent(const Optional<OwningNonNull<FileSystemEntryCallback>>& aSuccessCallback,
+                           const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback)
+{
+  if (!aSuccessCallback.WasPassed() && !aErrorCallback.WasPassed()) {
+    return;
+  }
+
+  if (mParentEntry) {
+    FileSystemEntryCallbackHelper::Call(aSuccessCallback, mParentEntry);
+    return;
+  }
+
+  FileSystemEntryCallbackHelper::Call(aSuccessCallback, this);
+}
+
+} // dom namespace
+} // mozilla namespace
diff --git a/dom/filesystem/compat/FileSystemEntry.h b/dom/filesystem/compat/FileSystemEntry.h
new file mode 100644
index 000000000..769fb8f3f
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemEntry.h
@@ -0,0 +1,89 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystemEntry_h
+#define mozilla_dom_FileSystemEntry_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/ErrorResult.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/FileSystemBinding.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsIGlobalObject.h"
+#include "nsWrapperCache.h"
+
+namespace mozilla {
+namespace dom {
+
+class FileSystem;
+class OwningFileOrDirectory;
+
+class FileSystemEntry
+  : public nsISupports
+  , public nsWrapperCache
+{
+public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(FileSystemEntry)
+
+  static already_AddRefed<FileSystemEntry>
+  Create(nsIGlobalObject* aGlobalObject,
+         const OwningFileOrDirectory& aFileOrDirectory,
+         FileSystem* aFileSystem);
+
+  nsIGlobalObject*
+  GetParentObject() const
+  {
+    return mParent;
+  }
+
+  virtual JSObject*
+  WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  virtual bool
+  IsFile() const
+  {
+    return false;
+  }
+
+  virtual bool
+  IsDirectory() const
+  {
+    return false;
+  }
+
+  virtual void
+  GetName(nsAString& aName, ErrorResult& aRv) const = 0;
+
+  virtual void
+  GetFullPath(nsAString& aFullPath, ErrorResult& aRv) const = 0;
+
+  void
+  GetParent(const Optional<OwningNonNull<FileSystemEntryCallback>>& aSuccessCallback,
+            const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback);
+
+  FileSystem*
+  Filesystem() const
+  {
+    return mFileSystem;
+  }
+
+protected:
+  FileSystemEntry(nsIGlobalObject* aGlobalObject,
+                  FileSystemEntry* aParentEntry,
+                  FileSystem* aFileSystem);
+  virtual ~FileSystemEntry();
+
+private:
+  nsCOMPtr<nsIGlobalObject> mParent;
+  RefPtr<FileSystemEntry> mParentEntry;
+  RefPtr<FileSystem> mFileSystem;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileSystemEntry_h
diff --git a/dom/filesystem/compat/FileSystemFileEntry.cpp b/dom/filesystem/compat/FileSystemFileEntry.cpp
new file mode 100644
index 000000000..6302df06d
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemFileEntry.cpp
@@ -0,0 +1,138 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FileSystemFileEntry.h"
+#include "CallbackRunnables.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/dom/MultipartBlobImpl.h"
+#include "mozilla/dom/FileSystemFileEntryBinding.h"
+
+namespace mozilla {
+namespace dom {
+
+namespace {
+
+class FileCallbackRunnable final : public Runnable
+{
+public:
+  FileCallbackRunnable(FileCallback* aCallback, ErrorCallback* aErrorCallback,
+                       File* aFile)
+    : mCallback(aCallback)
+    , mErrorCallback(aErrorCallback)
+    , mFile(aFile)
+  {
+    MOZ_ASSERT(aCallback);
+    MOZ_ASSERT(aFile);
+  }
+
+  NS_IMETHOD
+  Run() override
+  {
+    // Here we clone the File object.
+
+    nsAutoString name;
+    mFile->GetName(name);
+
+    nsAutoString type;
+    mFile->GetType(type);
+
+    nsTArray<RefPtr<BlobImpl>> blobImpls;
+    blobImpls.AppendElement(mFile->Impl());
+
+    ErrorResult rv;
+    RefPtr<BlobImpl> blobImpl =
+      MultipartBlobImpl::Create(Move(blobImpls), name, type, rv);
+    if (NS_WARN_IF(rv.Failed())) {
+      if (mErrorCallback) {
+        RefPtr<DOMException> exception =
+          DOMException::Create(rv.StealNSResult());
+        mErrorCallback->HandleEvent(*exception);
+      }
+
+      return NS_OK;
+    }
+
+    RefPtr<File> file = File::Create(mFile->GetParentObject(), blobImpl);
+    MOZ_ASSERT(file);
+
+    mCallback->HandleEvent(*file);
+    return NS_OK;
+  }
+
+private:
+  RefPtr<FileCallback> mCallback;
+  RefPtr<ErrorCallback> mErrorCallback;
+  RefPtr<File> mFile;
+};
+
+} // anonymous namespace
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(FileSystemFileEntry, FileSystemEntry, mFile)
+
+NS_IMPL_ADDREF_INHERITED(FileSystemFileEntry, FileSystemEntry)
+NS_IMPL_RELEASE_INHERITED(FileSystemFileEntry, FileSystemEntry)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(FileSystemFileEntry)
+NS_INTERFACE_MAP_END_INHERITING(FileSystemEntry)
+
+FileSystemFileEntry::FileSystemFileEntry(nsIGlobalObject* aGlobal,
+                                         File* aFile,
+                                         FileSystemDirectoryEntry* aParentEntry,
+                                         FileSystem* aFileSystem)
+  : FileSystemEntry(aGlobal, aParentEntry, aFileSystem)
+  , mFile(aFile)
+{
+  MOZ_ASSERT(aGlobal);
+  MOZ_ASSERT(mFile);
+}
+
+FileSystemFileEntry::~FileSystemFileEntry()
+{}
+
+JSObject*
+FileSystemFileEntry::WrapObject(JSContext* aCx,
+                                JS::Handle<JSObject*> aGivenProto)
+{
+  return FileSystemFileEntryBinding::Wrap(aCx, this, aGivenProto);
+}
+
+void
+FileSystemFileEntry::GetName(nsAString& aName, ErrorResult& aRv) const
+{
+  mFile->GetName(aName);
+}
+
+void
+FileSystemFileEntry::GetFullPath(nsAString& aPath, ErrorResult& aRv) const
+{
+  mFile->Impl()->GetDOMPath(aPath);
+  if (aPath.IsEmpty()) {
+    // We're under the root directory. webkitRelativePath
+    // (implemented as GetPath) is for cases when file is selected because its
+    // ancestor directory is selected. But that is not the case here, so need to
+    // manually prepend '/'.
+    nsAutoString name;
+    mFile->GetName(name);
+    aPath.AssignLiteral(FILESYSTEM_DOM_PATH_SEPARATOR_LITERAL);
+    aPath.Append(name);
+  }
+}
+
+void
+FileSystemFileEntry::GetFile(FileCallback& aSuccessCallback,
+                             const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback) const
+{
+  RefPtr<FileCallbackRunnable> runnable =
+    new FileCallbackRunnable(&aSuccessCallback,
+                             aErrorCallback.WasPassed()
+                               ? &aErrorCallback.Value() : nullptr,
+                             mFile);
+  DebugOnly<nsresult> rv = NS_DispatchToMainThread(runnable);
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_DispatchToMainThread failed");
+}
+
+} // dom namespace
+} // mozilla namespace
diff --git a/dom/filesystem/compat/FileSystemFileEntry.h b/dom/filesystem/compat/FileSystemFileEntry.h
new file mode 100644
index 000000000..06b76e9f8
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemFileEntry.h
@@ -0,0 +1,57 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystemFileEntry_h
+#define mozilla_dom_FileSystemFileEntry_h
+
+#include "mozilla/dom/FileSystemEntry.h"
+
+namespace mozilla {
+namespace dom {
+
+class File;
+class FileCallback;
+class FileSystemDirectoryEntry;
+
+class FileSystemFileEntry final : public FileSystemEntry
+{
+public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(FileSystemFileEntry, FileSystemEntry)
+
+  FileSystemFileEntry(nsIGlobalObject* aGlobalObject, File* aFile,
+                      FileSystemDirectoryEntry* aParentEntry,
+                      FileSystem* aFileSystem);
+
+  virtual JSObject*
+  WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+
+  virtual bool
+  IsFile() const override
+  {
+    return true;
+  }
+
+  virtual void
+  GetName(nsAString& aName, ErrorResult& aRv) const override;
+
+  virtual void
+  GetFullPath(nsAString& aFullPath, ErrorResult& aRv) const override;
+
+  void
+  GetFile(FileCallback& aSuccessCallback,
+          const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback) const;
+
+private:
+  ~FileSystemFileEntry();
+
+  RefPtr<File> mFile;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileSystemFileEntry_h
diff --git a/dom/filesystem/compat/FileSystemRootDirectoryEntry.cpp b/dom/filesystem/compat/FileSystemRootDirectoryEntry.cpp
new file mode 100644
index 000000000..68ce62aa2
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemRootDirectoryEntry.cpp
@@ -0,0 +1,146 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FileSystemRootDirectoryEntry.h"
+#include "FileSystemRootDirectoryReader.h"
+#include "mozilla/dom/FileSystemUtils.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(FileSystemRootDirectoryEntry,
+                                   FileSystemDirectoryEntry, mEntries)
+
+NS_IMPL_ADDREF_INHERITED(FileSystemRootDirectoryEntry, FileSystemDirectoryEntry)
+NS_IMPL_RELEASE_INHERITED(FileSystemRootDirectoryEntry, FileSystemDirectoryEntry)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(FileSystemRootDirectoryEntry)
+NS_INTERFACE_MAP_END_INHERITING(FileSystemDirectoryEntry)
+
+FileSystemRootDirectoryEntry::FileSystemRootDirectoryEntry(nsIGlobalObject* aGlobal,
+                                                           const Sequence<RefPtr<FileSystemEntry>>& aEntries,
+                                                           FileSystem* aFileSystem)
+  : FileSystemDirectoryEntry(aGlobal, nullptr, nullptr, aFileSystem)
+  , mEntries(aEntries)
+{
+  MOZ_ASSERT(aGlobal);
+}
+
+FileSystemRootDirectoryEntry::~FileSystemRootDirectoryEntry()
+{}
+
+void
+FileSystemRootDirectoryEntry::GetName(nsAString& aName, ErrorResult& aRv) const
+{
+  aName.Truncate();
+}
+
+void
+FileSystemRootDirectoryEntry::GetFullPath(nsAString& aPath, ErrorResult& aRv) const
+{
+  aPath.AssignLiteral(FILESYSTEM_DOM_PATH_SEPARATOR_LITERAL);
+}
+
+already_AddRefed<FileSystemDirectoryReader>
+FileSystemRootDirectoryEntry::CreateReader()
+{
+  RefPtr<FileSystemDirectoryReader> reader =
+    new FileSystemRootDirectoryReader(this, Filesystem(), mEntries);
+  return reader.forget();
+}
+
+void
+FileSystemRootDirectoryEntry::GetInternal(const nsAString& aPath,
+                                          const FileSystemFlags& aFlag,
+                                          const Optional<OwningNonNull<FileSystemEntryCallback>>& aSuccessCallback,
+                                          const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback,
+                                          GetInternalType aType)
+{
+  if (!aSuccessCallback.WasPassed() && !aErrorCallback.WasPassed()) {
+    return;
+  }
+
+  if (aFlag.mCreate) {
+    ErrorCallbackHelper::Call(GetParentObject(), aErrorCallback,
+                              NS_ERROR_DOM_SECURITY_ERR);
+    return;
+  }
+
+  nsTArray<nsString> parts;
+  if (!FileSystemUtils::IsValidRelativeDOMPath(aPath, parts)) {
+    ErrorCallbackHelper::Call(GetParentObject(), aErrorCallback,
+                              NS_ERROR_DOM_NOT_FOUND_ERR);
+    return;
+  }
+
+  MOZ_ASSERT(!parts.IsEmpty());
+
+  RefPtr<FileSystemEntry> entry;
+  for (uint32_t i = 0; i < mEntries.Length(); ++i) {
+    ErrorResult rv;
+    nsAutoString name;
+    mEntries[i]->GetName(name, rv);
+
+    if (NS_WARN_IF(rv.Failed())) {
+      ErrorCallbackHelper::Call(GetParentObject(), aErrorCallback,
+                                rv.StealNSResult());
+      return;
+    }
+
+    if (name == parts[0]) {
+      entry = mEntries[i];
+      break;
+    }
+  }
+
+  // Not found.
+  if (!entry) {
+    ErrorCallbackHelper::Call(GetParentObject(), aErrorCallback,
+                              NS_ERROR_DOM_NOT_FOUND_ERR);
+    return;
+  }
+
+  // No subdirectory in the path.
+  if (parts.Length() == 1) {
+    if ((entry->IsFile() && aType == eGetDirectory) ||
+        (entry->IsDirectory() && aType == eGetFile)) {
+      ErrorCallbackHelper::Call(GetParentObject(), aErrorCallback,
+                                NS_ERROR_DOM_TYPE_MISMATCH_ERR);
+      return;
+    }
+
+    if (aSuccessCallback.WasPassed()) {
+      RefPtr<EntryCallbackRunnable> runnable =
+        new EntryCallbackRunnable(&aSuccessCallback.Value(), entry);
+      DebugOnly<nsresult> rv = NS_DispatchToMainThread(runnable);
+      NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_DispatchToMainThread failed");
+    }
+    return;
+  }
+
+  // Subdirectories, but this is a file.
+  if (entry->IsFile()) {
+    ErrorCallbackHelper::Call(GetParentObject(), aErrorCallback,
+                              NS_ERROR_DOM_NOT_FOUND_ERR);
+    return;
+  }
+
+  // Let's recreate a path without the first directory.
+  nsAutoString path;
+  for (uint32_t i = 1, len = parts.Length(); i < len; ++i) {
+    path.Append(parts[i]);
+    if (i < len - 1) {
+      path.AppendLiteral(FILESYSTEM_DOM_PATH_SEPARATOR_LITERAL);
+    }
+  }
+
+  auto* directoryEntry = static_cast<FileSystemDirectoryEntry*>(entry.get());
+  directoryEntry->GetInternal(path, aFlag, aSuccessCallback, aErrorCallback,
+                              aType);
+}
+
+} // dom namespace
+} // mozilla namespace
diff --git a/dom/filesystem/compat/FileSystemRootDirectoryEntry.h b/dom/filesystem/compat/FileSystemRootDirectoryEntry.h
new file mode 100644
index 000000000..28c151ea2
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemRootDirectoryEntry.h
@@ -0,0 +1,53 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystemRootDirectoryEntry_h
+#define mozilla_dom_FileSystemRootDirectoryEntry_h
+
+#include "mozilla/dom/FileSystemDirectoryEntry.h"
+
+namespace mozilla {
+namespace dom {
+
+class FileSystemRootDirectoryEntry final : public FileSystemDirectoryEntry
+{
+public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(FileSystemRootDirectoryEntry, FileSystemDirectoryEntry)
+
+  FileSystemRootDirectoryEntry(nsIGlobalObject* aGlobalObject,
+                               const Sequence<RefPtr<FileSystemEntry>>& aEntries,
+                               FileSystem* aFileSystem);
+
+  virtual void
+  GetName(nsAString& aName, ErrorResult& aRv) const override;
+
+  virtual void
+  GetFullPath(nsAString& aFullPath, ErrorResult& aRv) const override;
+
+  virtual already_AddRefed<FileSystemDirectoryReader>
+  CreateReader() override;
+
+private:
+  ~FileSystemRootDirectoryEntry();
+
+  virtual void
+  GetInternal(const nsAString& aPath, const FileSystemFlags& aFlag,
+              const Optional<OwningNonNull<FileSystemEntryCallback>>& aSuccessCallback,
+              const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback,
+              GetInternalType aType) override;
+
+  void
+  Error(const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback,
+        nsresult aError) const;
+
+  Sequence<RefPtr<FileSystemEntry>> mEntries;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileSystemRootDirectoryEntry_h
diff --git a/dom/filesystem/compat/FileSystemRootDirectoryReader.cpp b/dom/filesystem/compat/FileSystemRootDirectoryReader.cpp
new file mode 100644
index 000000000..5b4a41752
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemRootDirectoryReader.cpp
@@ -0,0 +1,96 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FileSystemRootDirectoryReader.h"
+#include "CallbackRunnables.h"
+#include "nsIGlobalObject.h"
+
+namespace mozilla {
+namespace dom {
+
+namespace {
+
+class EntriesCallbackRunnable final : public Runnable
+{
+public:
+  EntriesCallbackRunnable(FileSystemEntriesCallback* aCallback,
+                          const Sequence<RefPtr<FileSystemEntry>>& aEntries)
+    : mCallback(aCallback)
+    , mEntries(aEntries)
+  {
+    MOZ_ASSERT(aCallback);
+  }
+
+  NS_IMETHOD
+  Run() override
+  {
+    Sequence<OwningNonNull<FileSystemEntry>> entries;
+    for (uint32_t i = 0; i < mEntries.Length(); ++i) {
+      if (!entries.AppendElement(mEntries[i].forget(), fallible)) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+    }
+
+    mCallback->HandleEvent(entries);
+    return NS_OK;
+  }
+
+private:
+  RefPtr<FileSystemEntriesCallback> mCallback;
+  Sequence<RefPtr<FileSystemEntry>> mEntries;
+};
+
+} // anonymous namespace
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(FileSystemRootDirectoryReader,
+                                   FileSystemDirectoryReader, mEntries)
+
+NS_IMPL_ADDREF_INHERITED(FileSystemRootDirectoryReader,
+                         FileSystemDirectoryReader)
+NS_IMPL_RELEASE_INHERITED(FileSystemRootDirectoryReader,
+                          FileSystemDirectoryReader)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(FileSystemRootDirectoryReader)
+NS_INTERFACE_MAP_END_INHERITING(FileSystemDirectoryReader)
+
+FileSystemRootDirectoryReader::FileSystemRootDirectoryReader(FileSystemDirectoryEntry* aParentEntry,
+                                                             FileSystem* aFileSystem,
+                                                             const Sequence<RefPtr<FileSystemEntry>>& aEntries)
+  : FileSystemDirectoryReader(aParentEntry, aFileSystem, nullptr)
+  , mEntries(aEntries)
+  , mAlreadyRead(false)
+{
+  MOZ_ASSERT(aParentEntry);
+  MOZ_ASSERT(aFileSystem);
+}
+
+FileSystemRootDirectoryReader::~FileSystemRootDirectoryReader()
+{}
+
+void
+FileSystemRootDirectoryReader::ReadEntries(FileSystemEntriesCallback& aSuccessCallback,
+                                           const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback,
+                                           ErrorResult& aRv)
+{
+  if (mAlreadyRead) {
+    RefPtr<EmptyEntriesCallbackRunnable> runnable =
+      new EmptyEntriesCallbackRunnable(&aSuccessCallback);
+    aRv = NS_DispatchToMainThread(runnable);
+    NS_WARNING_ASSERTION(!aRv.Failed(), "NS_DispatchToMainThread failed");
+    return;
+  }
+
+  // This object can be used only once.
+  mAlreadyRead = true;
+
+  RefPtr<EntriesCallbackRunnable> runnable =
+    new EntriesCallbackRunnable(&aSuccessCallback, mEntries);
+  aRv = NS_DispatchToMainThread(runnable);
+  NS_WARNING_ASSERTION(!aRv.Failed(), "NS_DispatchToMainThread failed");
+}
+
+} // dom namespace
+} // mozilla namespace
diff --git a/dom/filesystem/compat/FileSystemRootDirectoryReader.h b/dom/filesystem/compat/FileSystemRootDirectoryReader.h
new file mode 100644
index 000000000..54bca7726
--- /dev/null
+++ b/dom/filesystem/compat/FileSystemRootDirectoryReader.h
@@ -0,0 +1,41 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FileSystemRootDirectoryReader_h
+#define mozilla_dom_FileSystemRootDirectoryReader_h
+
+#include "FileSystemDirectoryReader.h"
+
+namespace mozilla {
+namespace dom {
+
+class FileSystemRootDirectoryReader final : public FileSystemDirectoryReader
+{
+public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(FileSystemRootDirectoryReader,
+                                           FileSystemDirectoryReader)
+
+  explicit FileSystemRootDirectoryReader(FileSystemDirectoryEntry* aParentEntry,
+                                         FileSystem* aFileSystem,
+                                         const Sequence<RefPtr<FileSystemEntry>>& aEntries);
+
+  virtual void
+  ReadEntries(FileSystemEntriesCallback& aSuccessCallback,
+              const Optional<OwningNonNull<ErrorCallback>>& aErrorCallback,
+              ErrorResult& aRv) override;
+
+private:
+  ~FileSystemRootDirectoryReader();
+
+  Sequence<RefPtr<FileSystemEntry>> mEntries;
+  bool mAlreadyRead;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_FileSystemRootDirectoryReader_h
diff --git a/dom/filesystem/compat/moz.build b/dom/filesystem/compat/moz.build
new file mode 100644
index 000000000..fc3f9482f
--- /dev/null
+++ b/dom/filesystem/compat/moz.build
@@ -0,0 +1,30 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+TEST_DIRS += ['tests']
+
+EXPORTS.mozilla.dom += [
+    'FileSystem.h',
+    'FileSystemDirectoryEntry.h',
+    'FileSystemDirectoryReader.h',
+    'FileSystemEntry.h',
+    'FileSystemFileEntry.h',
+]
+
+UNIFIED_SOURCES += [
+    'CallbackRunnables.cpp',
+    'FileSystem.cpp',
+    'FileSystemDirectoryEntry.cpp',
+    'FileSystemDirectoryReader.cpp',
+    'FileSystemEntry.cpp',
+    'FileSystemFileEntry.cpp',
+    'FileSystemRootDirectoryEntry.cpp',
+    'FileSystemRootDirectoryReader.cpp',
+]
+
+FINAL_LIBRARY = 'xul'
+
+include('/ipc/chromium/chromium-config.mozbuild')
diff --git a/dom/filesystem/compat/tests/mochitest.ini b/dom/filesystem/compat/tests/mochitest.ini
new file mode 100644
index 000000000..2b6eafb55
--- /dev/null
+++ b/dom/filesystem/compat/tests/mochitest.ini
@@ -0,0 +1,8 @@
+[DEFAULT]
+support-files =
+  script_entries.js
+  !/dom/html/test/form_submit_server.sjs
+
+[test_basic.html]
+[test_no_dnd.html]
+[test_formSubmission.html]
diff --git a/dom/filesystem/compat/tests/moz.build b/dom/filesystem/compat/tests/moz.build
new file mode 100644
index 000000000..3b13ba431
--- /dev/null
+++ b/dom/filesystem/compat/tests/moz.build
@@ -0,0 +1,7 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+MOCHITEST_MANIFESTS += ['mochitest.ini']
diff --git a/dom/filesystem/compat/tests/script_entries.js b/dom/filesystem/compat/tests/script_entries.js
new file mode 100644
index 000000000..8083214c9
--- /dev/null
+++ b/dom/filesystem/compat/tests/script_entries.js
@@ -0,0 +1,47 @@
+var { classes: Cc, interfaces: Ci, utils: Cu } = Components;
+Cu.importGlobalProperties(["File", "Directory"]);
+
+var tmpFile, tmpDir;
+
+addMessageListener("entries.open", function (e) {
+  tmpFile = Cc["@mozilla.org/file/directory_service;1"]
+              .getService(Ci.nsIDirectoryService)
+              .QueryInterface(Ci.nsIProperties)
+              .get('TmpD', Ci.nsIFile)
+  tmpFile.append('file.txt');
+  tmpFile.createUnique(Components.interfaces.nsIFile.FILE_TYPE, 0o600);
+
+  tmpDir = Cc["@mozilla.org/file/directory_service;1"]
+              .getService(Ci.nsIDirectoryService)
+              .QueryInterface(Ci.nsIProperties)
+              .get('TmpD', Ci.nsIFile)
+
+  tmpDir.append('dir-test');
+  tmpDir.createUnique(Components.interfaces.nsIFile.DIRECTORY_TYPE, 0o700);
+
+  var file1 = tmpDir.clone();
+  file1.append('foo.txt');
+  file1.create(Components.interfaces.nsIFile.NORMAL_FILE_TYPE, 0o600);
+
+  var dir1 = tmpDir.clone();
+  dir1.append('subdir');
+  dir1.create(Components.interfaces.nsIFile.DIRECTORY_TYPE, 0o700);
+
+  var file2 = dir1.clone();
+  file2.append('bar..txt'); // Note the double ..
+  file2.create(Components.interfaces.nsIFile.NORMAL_FILE_TYPE, 0o600);
+
+  var dir2 = dir1.clone();
+  dir2.append('subsubdir');
+  dir2.create(Components.interfaces.nsIFile.DIRECTORY_TYPE, 0o700);
+
+  sendAsyncMessage("entries.opened", {
+    data: [ new Directory(tmpDir.path), File.createFromNsIFile(tmpFile) ]
+  });
+});
+
+addMessageListener("entries.delete", function(e) {
+  tmpFile.remove(true);
+  tmpDir.remove(true);
+  sendAsyncMessage("entries.deleted");
+});
diff --git a/dom/filesystem/compat/tests/test_basic.html b/dom/filesystem/compat/tests/test_basic.html
new file mode 100644
index 000000000..85a7418d5
--- /dev/null
+++ b/dom/filesystem/compat/tests/test_basic.html
@@ -0,0 +1,494 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for Blink FileSystem API - subset</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+
+<body>
+<input id="entries" type="file"></input>
+<script type="application/javascript;version=1.7">
+
+var fileEntry;
+var directoryEntry;
+var script;
+
+function setup_tests() {
+  SpecialPowers.pushPrefEnv({"set": [["dom.webkitBlink.dirPicker.enabled", true],
+                                     ["dom.filesystem.pathcheck.disabled", true],
+                                     ["dom.webkitBlink.filesystem.enabled", true]]}, next);
+}
+
+function populate_entries() {
+  var url = SimpleTest.getTestFileURL("script_entries.js");
+  script = SpecialPowers.loadChromeScript(url);
+
+  function onOpened(message) {
+    var entries = document.getElementById('entries');
+    SpecialPowers.wrap(entries).mozSetDndFilesAndDirectories(message.data);
+    next();
+  }
+
+  script.addMessageListener("entries.opened", onOpened);
+  script.sendAsyncMessage("entries.open");
+}
+
+function test_entries() {
+  var entries = document.getElementById('entries');
+  ok("webkitEntries" in entries, "HTMLInputElement.webkitEntries");
+  is(entries.webkitEntries.length, 2, "HTMLInputElement.webkitEntries.length == 2");
+  is(entries.files.length, 1, "HTMLInputElement.files is still populated");
+
+  for (var i = 0; i < entries.webkitEntries.length; ++i) {
+    if (entries.webkitEntries[i].isFile) {
+      ok(!fileEntry, "We just want 1 fileEntry");
+      fileEntry = entries.webkitEntries[i];
+    } else {
+      ok(entries.webkitEntries[i].isDirectory, "If not a file, we have a directory.");
+      ok(!directoryEntry, "We just want 1 directoryEntry");
+      directoryEntry = entries.webkitEntries[i];
+    }
+  }
+
+  next();
+}
+
+function test_fileEntry() {
+  ok("name" in fileEntry, "We have a name.");
+  ok("fullPath" in fileEntry, "We have a fullPath.");
+  ok("filesystem" in fileEntry, "We have a filesystem.");
+
+  next();
+}
+
+function test_fileEntry_file() {
+  fileEntry.file(function(file) {
+    ok(file, "We have a file here!");
+    is(file.name, fileEntry.name, "Same file name.");
+    next();
+  }, function() {
+    ok(false, "Something when wrong!");
+  });
+}
+
+function test_fileEntry_getParent() {
+  fileEntry.getParent(function(entry) {
+    is(fileEntry.fullPath, entry.fullPath, "Top level FileEntry should return itself as parent.");
+    next();
+  }, function() {
+    ok(false, "This is wrong.");
+  });
+}
+
+function test_directoryEntry() {
+  ok("name" in directoryEntry, "We have a name.");
+  ok("fullPath" in directoryEntry, "We have a fullPath.");
+  ok("filesystem" in directoryEntry, "We have a filesystem.");
+
+  next();
+}
+
+function test_directoryEntry_createReader() {
+  var reader = directoryEntry.createReader();
+  ok(reader, "We have a DirectoryReader");
+
+  reader.readEntries(function(a) {
+    ok(Array.isArray(a), "We want an array.");
+    is(a.length, 2, "reader.readyEntries returns 2 elements.");
+
+    for (var i = 0; i < 2; ++i) {
+      ok(a[i].name == "subdir" || a[i].name == "foo.txt", "Correct names");
+      is(a[i].fullPath, directoryEntry.fullPath + "/" + a[i].name, "FullPath is correct");
+    }
+
+    // Called twice:
+    reader.readEntries(function(a) {
+      ok(Array.isArray(a), "We want an array.");
+      is(a.length, 0, "reader.readyEntries returns 0 elements.");
+      next();
+    }, function() {
+      ok(false, "Something when wrong!");
+    });
+
+  }, function() {
+    ok(false, "Something when wrong!");
+  });
+}
+
+function test_directoryEntry_getParent() {
+  directoryEntry.getParent(function(entry) {
+    is(directoryEntry.fullPath, entry.fullPath, "Top level FileEntry should return itself as parent.");
+    next();
+  }, function() {
+    ok(false, "This is wrong.");
+  });
+}
+
+function test_directoryEntry_getFile_securityError() {
+  directoryEntry.getFile("foo", { create: true },
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "SecurityError", "This must generate a SecurityError.");
+    next();
+  });
+}
+
+function test_directoryEntry_getFile_typeMismatchError() {
+  directoryEntry.getFile("subdir", {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "TypeMismatchError", "This must generate a TypeMismatchError.");
+    next();
+  });
+}
+
+function test_directoryEntry_getFile_nonValidPath() {
+  directoryEntry.getFile("../../", {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "NotFoundError", "This must generate a NotFoundError.");
+    next();
+  });
+}
+
+function test_directoryEntry_getFile_nonExistingPath() {
+  directoryEntry.getFile("foo_bar.txt", {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "NotFoundError", "This must generate a NotFoundError.");
+    next();
+  });
+}
+
+function test_directoryEntry_getFile_simple() {
+  directoryEntry.getFile("foo.txt", {},
+  function(e) {
+    is(e.name, "foo.txt", "We have the right FileEntry.");
+    test_getParent(e, directoryEntry, /* nested */ false);
+  }, function(e) {
+    ok(false, "This should not happen.");
+  });
+}
+
+function test_directoryEntry_getFile_deep() {
+  directoryEntry.getFile("subdir/bar..txt", {},
+  function(e) {
+    is(e.name, "bar..txt", "We have the right FileEntry.");
+    test_getParent(e, directoryEntry, /* nested */ true);
+  }, function(e) {
+    ok(false, "This should not happen.");
+  });
+}
+
+function test_directoryEntry_getDirectory_securityError() {
+  directoryEntry.getDirectory("foo", { create: true },
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "SecurityError", "This must generate a SecurityError.");
+    next();
+  });
+}
+
+function test_directoryEntry_getDirectory_typeMismatchError() {
+  directoryEntry.getDirectory("foo.txt", {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "TypeMismatchError", "This must generate a TypeMismatchError.");
+    next();
+  });
+}
+
+function test_directoryEntry_getDirectory_nonValidPath() {
+  directoryEntry.getDirectory("../../", {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "NotFoundError", "This must generate a NotFoundError.");
+    next();
+  });
+}
+
+function test_directoryEntry_getDirectory_nonExistingPath() {
+  directoryEntry.getDirectory("non_existing_dir", {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "NotFoundError", "This must generate a NotFoundError.");
+    next();
+  });
+}
+
+function test_directoryEntry_getDirectory_simple() {
+  directoryEntry.getDirectory("subdir", {},
+  function(e) {
+    is(e.name, "subdir", "We have the right DirectoryEntry.");
+    test_getParent(e, directoryEntry, /* nested */ false);
+  }, function(e) {
+    ok(false, "This should not happen.");
+  });
+}
+
+function test_directoryEntry_getDirectory_deep() {
+  directoryEntry.getDirectory("subdir/subsubdir", {},
+  function(e) {
+    is(e.name, "subsubdir", "We have the right DirectoryEntry.");
+    test_getParent(e, directoryEntry, /* nested */ true);
+  }, function(e) {
+    ok(false, "This should not happen.");
+  });
+}
+
+function test_filesystem() {
+  is(fileEntry.filesystem, directoryEntry.filesystem, "FileSystem object is shared.");
+
+  var fs = fileEntry.filesystem;
+  ok(fs.name, "FileSystem.name exists.");
+  ok(fs.root, "FileSystem has a root.");
+
+  is(fs.root.name, "", "FileSystem.root.name must be an empty string.");
+  is(fs.root.fullPath, "/", "FileSystem.root.fullPath must be '/'");
+
+  reader = fs.root.createReader();
+  reader.readEntries(function(a) {
+    ok(Array.isArray(a), "We want an array.");
+    is(a.length, 2, "reader.readyEntries returns 2 elements.");
+    next();
+  }, function() {
+    ok(false, "Something when wrong!");
+  });
+}
+
+function test_root_getFile_securityError() {
+  fileEntry.filesystem.root.getFile("foo", { create: true },
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "SecurityError", "This must generate a SecurityError.");
+    next();
+  });
+}
+
+function test_root_getFile_typeMismatchError() {
+  fileEntry.filesystem.root.getFile(directoryEntry.name, {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "TypeMismatchError", "This must generate a TypeMismatchError.");
+    next();
+  });
+}
+
+function test_root_getFile_nonValidPath() {
+  fileEntry.filesystem.root.getFile("../../", {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "NotFoundError", "This must generate a NotFoundError.");
+    next();
+  });
+}
+
+function test_root_getFile_nonExistingPath() {
+  fileEntry.filesystem.root.getFile("existing.txt", {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "NotFoundError", "This must generate a NotFoundError.");
+    next();
+  });
+}
+
+function test_root_getFile_simple() {
+  fileEntry.filesystem.root.getFile(fileEntry.name, {},
+  function(e) {
+    is(e.name, fileEntry.name, "We have the right FileEntry.");
+    next();
+  }, function(e) {
+    ok(false, "This should not happen.");
+  });
+}
+
+function test_root_getFile_deep() {
+  fileEntry.filesystem.root.getFile(directoryEntry.name + "/subdir/bar..txt", {},
+  function(e) {
+    is(e.name, "bar..txt", "We have the right FileEntry.");
+    next();
+  }, function(e) {
+    ok(false, "This should not happen.");
+  });
+}
+
+function test_root_getDirectory_securityError() {
+  fileEntry.filesystem.root.getDirectory("foo", { create: true },
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "SecurityError", "This must generate a SecurityError.");
+    next();
+  });
+}
+
+function test_root_getDirectory_typeMismatchError() {
+  fileEntry.filesystem.root.getDirectory(fileEntry.name, {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "TypeMismatchError", "This must generate a TypeMismatchError.");
+    next();
+  });
+}
+
+function test_root_getDirectory_nonValidPath() {
+  fileEntry.filesystem.root.getDirectory("../../", {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "NotFoundError", "This must generate a NotFoundError.");
+    next();
+  });
+}
+
+function test_root_getDirectory_nonExistingPath() {
+  fileEntry.filesystem.root.getDirectory("404", {},
+  function() {
+    ok(false, "This should not happen.");
+  }, function(e) {
+    is(e.name, "NotFoundError", "This must generate a NotFoundError.");
+    next();
+  });
+}
+
+function test_root_getDirectory_simple() {
+  fileEntry.filesystem.root.getDirectory(directoryEntry.name, {},
+  function(e) {
+    is(e.name, directoryEntry.name, "We have the right DirectoryEntry.");
+    next();
+  }, function(e) {
+    ok(false, "This should not happen.");
+  });
+}
+
+function test_root_getDirectory_deep() {
+  fileEntry.filesystem.root.getDirectory(directoryEntry.name + "/subdir/subsubdir", {},
+  function(e) {
+    is(e.name, "subsubdir", "We have the right DirectoryEntry.");
+    next();
+  }, function(e) {
+    ok(false, "This should not happen.");
+  });
+}
+
+function cleanUpTestingFiles() {
+  script.addMessageListener("entries.deleted", function onDeleted() {
+    script.removeMessageListener("entries.deleted");
+    script.destroy();
+    next();
+  });
+
+  script.sendAsyncMessage("entries.delete");
+}
+
+function test_getParent(entry, parentEntry, nested) {
+  entry.getParent(function(e) {
+    ok(e, "We have a parent Entry.");
+    if (!nested) {
+      is (e, parentEntry, "Parent entry matches");
+      next();
+    } else {
+      test_getParent(e, parentEntry, false);
+    }
+  }, function(e) {
+    ok(false, "This should not happen.");
+  });
+}
+
+function test_webkitRelativePath() {
+  fileEntry.file(function(file1) {
+    ok(file1, "We have a file here!");
+    ok(!file1.webkitRelativePath, "webkitRelativePath is an empty string");
+
+    fileEntry.file(function(file2) {
+      ok(file2, "We have a file here!");
+      ok(!file2.webkitRelativePath, "webkitRelativePath is an empty string");
+      isnot(file1, file2, "The 2 files are not the same");
+
+      next();
+    }, function() {
+      ok(false, "Something when wrong!");
+    });
+  }, function() {
+    ok(false, "Something when wrong!");
+  });
+}
+
+var tests = [
+  setup_tests,
+  populate_entries,
+
+  test_entries,
+
+  test_fileEntry,
+  test_fileEntry_file,
+  test_fileEntry_getParent,
+
+  test_directoryEntry,
+  test_directoryEntry_createReader,
+  test_directoryEntry_getParent,
+
+  test_directoryEntry_getFile_securityError,
+  test_directoryEntry_getFile_typeMismatchError,
+  test_directoryEntry_getFile_nonValidPath,
+  test_directoryEntry_getFile_nonExistingPath,
+  test_directoryEntry_getFile_simple,
+  test_directoryEntry_getFile_deep,
+
+  test_directoryEntry_getDirectory_securityError,
+  test_directoryEntry_getDirectory_typeMismatchError,
+  test_directoryEntry_getDirectory_nonValidPath,
+  test_directoryEntry_getDirectory_nonExistingPath,
+  test_directoryEntry_getDirectory_simple,
+  test_directoryEntry_getDirectory_deep,
+
+  test_filesystem,
+
+  test_root_getFile_securityError,
+  test_root_getFile_typeMismatchError,
+  test_root_getFile_nonValidPath,
+  test_root_getFile_nonExistingPath,
+  test_root_getFile_simple,
+  test_root_getFile_deep,
+
+  test_root_getDirectory_securityError,
+  test_root_getDirectory_typeMismatchError,
+  test_root_getDirectory_nonValidPath,
+  test_root_getDirectory_nonExistingPath,
+  test_root_getDirectory_simple,
+  test_root_getDirectory_deep,
+
+  test_webkitRelativePath,
+
+  cleanUpTestingFiles,
+];
+
+function next() {
+  if (!tests.length) {
+    SimpleTest.finish();
+    return;
+  }
+
+  var test = tests.shift();
+  test();
+}
+
+SimpleTest.waitForExplicitFinish();
+next();
+</script>
+</body>
+</html>
diff --git a/dom/filesystem/compat/tests/test_formSubmission.html b/dom/filesystem/compat/tests/test_formSubmission.html
new file mode 100644
index 000000000..0c04b8bf1
--- /dev/null
+++ b/dom/filesystem/compat/tests/test_formSubmission.html
@@ -0,0 +1,267 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for Directory form submission</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+  <meta http-equiv="Content-Type" content="text/html;charset=utf-8">
+</head>
+<body onload="return next();">
+
+<iframe name="target_iframe" id="target_iframe"></iframe>
+
+<form action="../../../html/test/form_submit_server.sjs" target="target_iframe" id="form"
+      method="POST" enctype="multipart/form-data">
+</form>
+
+<script class="testbody" type="text/javascript;version=1.8">
+
+var form;
+var iframe;
+var input;
+var xhr;
+
+function setup_tests() {
+  form = document.getElementById("form");
+
+  iframe = document.getElementById("target_iframe");
+  iframe.onload = function() {
+    info("Frame loaded!");
+    next();
+  }
+
+  SpecialPowers.pushPrefEnv({"set": [["dom.input.dirpicker", true],
+                                     ["dom.webkitBlink.dirPicker.enabled", true],
+                                     ["dom.filesystem.pathcheck.disabled", true],
+                                     ["dom.webkitBlink.filesystem.enabled", true]]}, next);
+}
+
+function populate_entries(webkitDirectory) {
+  if (input) {
+    form.removeChild(input);
+  }
+
+  input = document.createElement('input');
+  input.setAttribute('id', 'input');
+  input.setAttribute('type', 'file');
+  input.setAttribute('name', 'input');
+
+  if (webkitDirectory) {
+    input.setAttribute('webkitdirectory', 'true');
+  }
+
+  form.appendChild(input);
+
+  var url = SimpleTest.getTestFileURL("script_entries.js");
+  var script = SpecialPowers.loadChromeScript(url);
+
+  function onOpened(message) {
+    input.addEventListener("change", function onChange() {
+      input.removeEventListener("change", onChange);
+      next();
+    });
+
+    SpecialPowers.wrap(input).mozSetDndFilesAndDirectories([message.data[0]]);
+    script.destroy();
+  }
+
+  script.addMessageListener("entries.opened", onOpened);
+  script.sendAsyncMessage("entries.open");
+}
+
+function setup_plain() {
+  info("Preparing for a plain text submission...");
+  form.action = "../../../html/test/form_submit_server.sjs?plain";
+  form.method = "POST";
+  form.enctype = "text/plain";
+  form.submit();
+}
+
+function test_plain() {
+  var content = iframe.contentDocument.documentElement.textContent;
+  var submission = JSON.parse(content);
+  input.getFilesAndDirectories().then(function(array) {
+    is(submission, array.map(function(v) {
+       return "input=" + v.name + "\r\n";
+    }).join(""), "Data match");
+
+    next();
+  });
+}
+
+function setup_urlencoded() {
+  info("Preparing for a urlencoded submission...");
+  form.action = "../../../html/test/form_submit_server.sjs?url";
+  form.method = "POST";
+  form.enctype = "application/x-www-form-urlencoded";
+  form.submit();
+}
+
+function setup_urlencoded_get() {
+  info("Preparing for a urlencoded+GET submission...");
+  form.action = "../../../html/test/form_submit_server.sjs?xxyy";
+  form.method = "GET";
+  form.enctype = "";
+  form.submit();
+}
+
+function setup_urlencoded_empty() {
+  info("Preparing for a urlencoded+default values submission...");
+  form.action = "../../../html/test/form_submit_server.sjs";
+  form.method = "";
+  form.enctype = "";
+  form.submit();
+}
+
+function test_urlencoded() {
+  var content = iframe.contentDocument.documentElement.textContent;
+  var submission = JSON.parse(content);
+  input.getFilesAndDirectories().then(function(array) {
+    is(submission, array.map(function(v) {
+       return "input=" + v.name;
+    }).join("&"), "Data match");
+
+    next();
+  });
+}
+
+function setup_formData() {
+  info("Preparing for a fromData submission...");
+
+  xhr = new XMLHttpRequest();
+  xhr.onload = next;
+  xhr.open("POST", "../../../html/test/form_submit_server.sjs");
+  xhr.send(new FormData(form));
+}
+
+function test_multipart() {
+  var submission = JSON.parse(xhr.responseText);
+  input.getFilesAndDirectories().then(function(array) {
+    is(submission.length, array.length, "Same length");
+
+    for (var i = 0; i < array.length; ++i) {
+      if (array[i] instanceof Directory) {
+        is(submission[i].headers["Content-Disposition"],
+           "form-data; name=\"input\"; filename=\"/" + array[i].name + "\"",
+           "Correct Content-Disposition");
+        is(submission[i].headers["Content-Type"], "application/octet-stream",
+           "Correct Content-Type");
+        is(submission[i].body, "", "Correct body");
+      } else {
+        ok(array[i] instanceof File);
+        is(submission[i].headers["Content-Disposition"],
+           "form-data; name=\"input\"; filename=\"" + array[i].name + "\"",
+           "Correct Content-Disposition");
+        is(submission[i].headers["Content-Type"], array[i].type,
+           "Correct Content-Type");
+        is(submission[i].body, "", "Correct body");
+      }
+    }
+    next();
+  });
+}
+
+function test_webkit_plain() {
+  var content = iframe.contentDocument.documentElement.textContent;
+  var submission = JSON.parse(content);
+
+  input.getFiles(true).then(function(array) {
+    is(submission, array.map(function(v) {
+       return "input=" + v.name + "\r\n";
+    }).join(""), "Data match");
+
+    next();
+  });
+}
+
+function test_webkit_urlencoded() {
+  var content = iframe.contentDocument.documentElement.textContent;
+  var submission = JSON.parse(content);
+  input.getFiles(true).then(function(array) {
+    is(submission, array.map(function(v) {
+       return "input=" + v.name;
+    }).join("&"), "Data match");
+
+    next();
+  });
+}
+
+function test_webkit_multipart() {
+  var submission = JSON.parse(xhr.responseText);
+  input.getFiles(true).then(function(array) {
+    is(submission.length, array.length, "Same length");
+
+    for (var i = 0; i < array.length; ++i) {
+      if (array[i] instanceof Directory) {
+        is(submission[i].headers["Content-Disposition"],
+           "form-data; name=\"input\"; filename=\"/" + array[i].name + "\"",
+           "Correct Content-Disposition");
+        is(submission[i].headers["Content-Type"], "application/octet-stream",
+           "Correct Content-Type");
+        is(submission[i].body, "", "Correct body");
+      } else {
+        ok(array[i] instanceof File);
+        is(submission[i].headers["Content-Disposition"],
+           "form-data; name=\"input\"; filename=\"" + array[i].webkitRelativePath + "\"",
+           "Correct Content-Disposition");
+        is(submission[i].headers["Content-Type"], array[i].type,
+           "Correct Content-Type");
+        is(submission[i].body, "", "Correct body");
+      }
+    }
+    next();
+  });
+}
+
+var tests = [
+  setup_tests,
+  function() { populate_entries(false); },
+
+  setup_plain,
+  test_plain,
+
+  setup_urlencoded,
+  test_urlencoded,
+
+  setup_urlencoded_get,
+  test_urlencoded,
+
+  setup_urlencoded_empty,
+  test_urlencoded,
+
+  setup_formData,
+  test_multipart,
+
+  function() { populate_entries(true); },
+
+  setup_plain,
+  test_webkit_plain,
+
+  setup_urlencoded,
+  test_webkit_urlencoded,
+
+  setup_urlencoded_get,
+  test_webkit_urlencoded,
+
+  setup_urlencoded_empty,
+  test_webkit_urlencoded,
+
+  setup_formData,
+  test_webkit_multipart,
+];
+
+function next() {
+  if (!tests.length) {
+    SimpleTest.finish();
+    return;
+  }
+
+  var test = tests.shift();
+  test();
+}
+
+SimpleTest.waitForExplicitFinish();
+
+</script>
+</body>
+</html>
diff --git a/dom/filesystem/compat/tests/test_no_dnd.html b/dom/filesystem/compat/tests/test_no_dnd.html
new file mode 100644
index 000000000..a78ac108f
--- /dev/null
+++ b/dom/filesystem/compat/tests/test_no_dnd.html
@@ -0,0 +1,85 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for Blink FileSystem API - no DND == no webkitEntries</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+
+<body>
+<script type="application/javascript;version=1.7">
+
+var fileEntry;
+var directoryEntry;
+var script;
+var entries;
+
+function setup_tests() {
+  SpecialPowers.pushPrefEnv({"set": [["dom.webkitBlink.dirPicker.enabled", true],
+                                     ["dom.filesystem.pathcheck.disabled", true],
+                                     ["dom.webkitBlink.filesystem.enabled", true]]}, next);
+}
+
+function populate_entries() {
+  entries = document.createElement('input');
+  entries.setAttribute('type', 'file');
+  document.body.appendChild(entries);
+
+  var url = SimpleTest.getTestFileURL("script_entries.js");
+  script = SpecialPowers.loadChromeScript(url);
+
+  function onOpened(message) {
+    for (var i = 0 ; i < message.data.length; ++i) {
+      if (message.data[i] instanceof File) {
+        SpecialPowers.wrap(entries).mozSetFileArray([message.data[i]]);
+        next();
+      }
+    }
+  }
+
+  script.addMessageListener("entries.opened", onOpened);
+  script.sendAsyncMessage("entries.open");
+}
+
+function test_entries() {
+  ok("webkitEntries" in entries, "HTMLInputElement.webkitEntries");
+  is(entries.webkitEntries.length, 0, "HTMLInputElement.webkitEntries.length == 0");
+  is(entries.files.length, 1, "HTMLInputElement.files is still populated");
+
+  next();
+}
+
+function cleanUpTestingFiles() {
+  script.addMessageListener("entries.deleted", function onDeleted() {
+    script.removeMessageListener("entries.deleted");
+    script.destroy();
+    next();
+  });
+
+  script.sendAsyncMessage("entries.delete");
+}
+
+var tests = [
+  setup_tests,
+  populate_entries,
+
+  test_entries,
+
+  cleanUpTestingFiles,
+];
+
+function next() {
+  if (!tests.length) {
+    SimpleTest.finish();
+    return;
+  }
+
+  var test = tests.shift();
+  test();
+}
+
+SimpleTest.waitForExplicitFinish();
+next();
+</script>
+</body>
+</html>
diff --git a/dom/filesystem/moz.build b/dom/filesystem/moz.build
new file mode 100644
index 000000000..6e516c3a7
--- /dev/null
+++ b/dom/filesystem/moz.build
@@ -0,0 +1,48 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DIRS += ['compat']
+
+TEST_DIRS += ['tests']
+
+EXPORTS.mozilla.dom += [
+    'Directory.h',
+    'FileSystemBase.h',
+    'FileSystemRequestParent.h',
+    'FileSystemSecurity.h',
+    'FileSystemTaskBase.h',
+    'FileSystemUtils.h',
+    'GetFilesHelper.h',
+    'OSFileSystem.h',
+]
+
+UNIFIED_SOURCES += [
+    'Directory.cpp',
+    'FileSystemBase.cpp',
+    'FileSystemRequestParent.cpp',
+    'FileSystemSecurity.cpp',
+    'FileSystemTaskBase.cpp',
+    'FileSystemUtils.cpp',
+    'GetDirectoryListingTask.cpp',
+    'GetFileOrDirectoryTask.cpp',
+    'GetFilesHelper.cpp',
+    'GetFilesTask.cpp',
+    'OSFileSystem.cpp',
+]
+
+FINAL_LIBRARY = 'xul'
+
+IPDL_SOURCES += [
+    'PFileSystemParams.ipdlh',
+    'PFileSystemRequest.ipdl',
+]
+
+include('/ipc/chromium/chromium-config.mozbuild')
+
+LOCAL_INCLUDES += [
+    '/dom/base',
+    '/dom/workers',
+]
diff --git a/dom/filesystem/tests/filesystem_commons.js b/dom/filesystem/tests/filesystem_commons.js
new file mode 100644
index 000000000..4f7234121
--- /dev/null
+++ b/dom/filesystem/tests/filesystem_commons.js
@@ -0,0 +1,103 @@
+function createPath(parentDir, dirOrFile) {
+  return parentDir.path + (parentDir.path == '/' ? '' : '/') + dirOrFile.name;
+}
+
+function createRelativePath(parentDir, dirOrFile) {
+  let path = createPath(parentDir, dirOrFile);
+  is(path[0], "/", "The full path should start with '/'");
+  return path.substring(1);
+}
+
+function setup_tests(aNext) {
+  SimpleTest.requestLongerTimeout(2);
+  SpecialPowers.pushPrefEnv({"set": [["dom.input.dirpicker", true],
+                                     ["dom.filesystem.pathcheck.disabled", true],
+                                     ["dom.webkitBlink.dirPicker.enabled", true]]}, aNext);
+}
+
+function test_basic(aDirectory, aNext) {
+  ok(aDirectory, "Directory exists.");
+  ok(aDirectory instanceof Directory, "We have a directory.");
+  is(aDirectory.path, '/' + aDirectory.name, "directory.path must be '/'+name");
+  aNext();
+}
+
+function test_getFilesAndDirectories(aDirectory, aRecursive, aNext) {
+  function checkSubDir(dir) {
+    return dir.getFilesAndDirectories().then(
+      function(data) {
+        for (var i = 0; i < data.length; ++i) {
+          ok (data[i] instanceof File || data[i] instanceof Directory, "Just Files or Directories");
+          if (data[i] instanceof Directory) {
+            isnot(data[i].name, '/', "Subdirectory should be called with the leafname");
+            isnot(data[i].path, '/', "Subdirectory path should be called with the leafname");
+            isnot(data[i].path, dir.path, "Subdirectory path should contain the parent path.");
+            is(data[i].path, createPath(dir, data[i]), "Subdirectory path should be called parentdir.path + '/' + leafname: " + data[i].path);
+          }
+
+          if (data[i] instanceof File) {
+            is(data[i].webkitRelativePath, createRelativePath(dir, data[i]), "File.webkitRelativePath should be called: parentdir.path + '/' + file.name: " + data[i].webkitRelativePath);
+          }
+        }
+      }
+    );
+  }
+
+  aDirectory.getFilesAndDirectories().then(
+    function(data) {
+      ok(data.length, "We should have some data.");
+      var promises = [];
+      for (var i = 0; i < data.length; ++i) {
+        ok (data[i] instanceof File || data[i] instanceof Directory, "Just Files or Directories: " + data[i].name);
+        if (data[i] instanceof Directory) {
+          isnot(data[i].name, '/', "Subdirectory should be called with the leafname");
+          is(data[i].path, createPath(aDirectory, data[i]), "Subdirectory path should be called parentdir.path + '/' + leafname: " + data[i].path);
+          if (aRecursive) {
+            promises.push(checkSubDir(data[i]));
+          }
+        }
+
+        if (data[i] instanceof File) {
+          is(data[i].webkitRelativePath, createRelativePath(aDirectory, data[i]), "File.webkitRelativePath should be called file.name: " + data[i].webkitRelativePath);
+        }
+      }
+
+      return Promise.all(promises);
+    },
+    function() {
+      ok(false, "Something when wrong");
+    }
+  ).then(aNext);
+}
+
+function test_getFiles(aDirectory, aRecursive, aNext) {
+  aDirectory.getFiles(aRecursive).then(
+    function(data) {
+      for (var i = 0; i < data.length; ++i) {
+        ok(data[i] instanceof File, "File: " + data[i].name);
+        is(aDirectory.path[0], '/', "Directory path must start with '/'");
+        ok(data[i].webkitRelativePath.indexOf(aDirectory.path.substring(1)) == 0 &&
+           data[i].webkitRelativePath.indexOf('/' + data[i].name) + ('/' + data[i].name).length == data[i].webkitRelativePath.length,
+           "File.webkitRelativePath should be called dir.path + '/' + file.name: " + data[i].webkitRelativePath);
+      }
+    },
+    function() {
+      ok(false, "Something when wrong");
+    }
+  ).then(aNext);
+}
+
+function test_getFiles_recursiveComparison(aDirectory, aNext) {
+  aDirectory.getFiles(true).then(function(data) {
+    is(data.length, 2, "Only 2 files for this test.");
+    ok(data[0].name == 'foo.txt' || data[0].name == 'bar.txt', "First filename matches");
+    ok(data[1].name == 'foo.txt' || data[1].name == 'bar.txt', "Second filename matches");
+  }).then(function() {
+    return aDirectory.getFiles(false);
+  }).then(function(data) {
+    is(data.length, 1, "Only 1 file for this test.");
+    ok(data[0].name == 'foo.txt' || data[0].name == 'bar.txt', "First filename matches");
+  }).catch(function() {
+    ok(false, "Something when wrong");
+  }).then(aNext);
+}
diff --git a/dom/filesystem/tests/mochitest.ini b/dom/filesystem/tests/mochitest.ini
new file mode 100644
index 000000000..649016886
--- /dev/null
+++ b/dom/filesystem/tests/mochitest.ini
@@ -0,0 +1,10 @@
+[DEFAULT]
+support-files =
+  filesystem_commons.js
+  script_fileList.js
+  worker_basic.js
+
+[test_basic.html]
+[test_webkitdirectory.html]
+[test_worker_basic.html]
+[test_bug1319088.html]
diff --git a/dom/filesystem/tests/moz.build b/dom/filesystem/tests/moz.build
new file mode 100644
index 000000000..3b13ba431
--- /dev/null
+++ b/dom/filesystem/tests/moz.build
@@ -0,0 +1,7 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+MOCHITEST_MANIFESTS += ['mochitest.ini']
diff --git a/dom/filesystem/tests/script_fileList.js b/dom/filesystem/tests/script_fileList.js
new file mode 100644
index 000000000..89fd04cab
--- /dev/null
+++ b/dom/filesystem/tests/script_fileList.js
@@ -0,0 +1,129 @@
+var { classes: Cc, interfaces: Ci, utils: Cu } = Components;
+Cu.importGlobalProperties(["File"]);
+
+function createProfDFile() {
+  return Cc["@mozilla.org/file/directory_service;1"]
+           .getService(Ci.nsIDirectoryService)
+           .QueryInterface(Ci.nsIProperties)
+           .get('ProfD', Ci.nsIFile);
+}
+
+// Creates a parametric arity directory hierarchy as a function of depth.
+// Each directory contains one leaf file, and subdirectories of depth [1, depth).
+// e.g. for depth 3:
+//
+// subdir3
+// - file.txt
+// - subdir2
+//   - file.txt
+//   - subdir1
+//     - file.txt
+// - subdir1
+//   - file.txt
+//
+// Returns the parent directory of the subtree.
+function createTreeFile(depth, parent) {
+  if (!parent) {
+    parent = Cc["@mozilla.org/file/directory_service;1"]
+                .getService(Ci.nsIDirectoryService)
+                .QueryInterface(Ci.nsIProperties)
+                .get('TmpD', Ci.nsIFile);
+    parent.append('dir-tree-test');
+    parent.createUnique(Components.interfaces.nsIFile.DIRECTORY_TYPE, 0o700);
+  }
+
+  var nextFile = parent.clone();
+  if (depth == 0) {
+    nextFile.append('file.txt');
+    nextFile.create(Components.interfaces.nsIFile.NORMAL_FILE_TYPE, 0o600);
+  } else {
+    nextFile.append('subdir' + depth);
+    nextFile.createUnique(Components.interfaces.nsIFile.DIRECTORY_TYPE, 0o700);
+    // Decrement the maximal depth by one for each level of nesting.
+    for (i = 0; i < depth; i++) {
+      createTreeFile(i, nextFile);
+    }
+  }
+
+  return parent;
+}
+
+function createRootFile() {
+  var testFile = createProfDFile();
+
+  // Let's go back to the root of the FileSystem
+  while (true) {
+    var parent = testFile.parent;
+    if (!parent) {
+      break;
+    }
+
+    testFile = parent;
+  }
+
+  return testFile;
+}
+
+function createTestFile() {
+  var tmpFile = Cc["@mozilla.org/file/directory_service;1"]
+                  .getService(Ci.nsIDirectoryService)
+                  .QueryInterface(Ci.nsIProperties)
+                  .get('TmpD', Ci.nsIFile)
+  tmpFile.append('dir-test');
+  tmpFile.createUnique(Components.interfaces.nsIFile.DIRECTORY_TYPE, 0o700);
+
+  var file1 = tmpFile.clone();
+  file1.append('foo.txt');
+  file1.create(Components.interfaces.nsIFile.NORMAL_FILE_TYPE, 0o600);
+
+  var dir = tmpFile.clone();
+  dir.append('subdir');
+  dir.create(Components.interfaces.nsIFile.DIRECTORY_TYPE, 0o700);
+
+  var file2 = dir.clone();
+  file2.append('bar.txt');
+  file2.create(Components.interfaces.nsIFile.NORMAL_FILE_TYPE, 0o600);
+
+  return tmpFile;
+}
+
+addMessageListener("dir.open", function (e) {
+  var testFile;
+
+  switch (e.path) {
+    case 'ProfD':
+      // Note that files in the profile directory are not guaranteed to persist-
+      // see bug 1284742.
+      testFile = createProfDFile();
+      break;
+
+    case 'root':
+      testFile = createRootFile();
+      break;
+
+    case 'test':
+      testFile = createTestFile();
+      break;
+
+    case 'tree':
+      testFile = createTreeFile(3);
+      break;
+  }
+
+  sendAsyncMessage("dir.opened", {
+    dir: testFile.path,
+    name: testFile.leafName
+  });
+});
+
+addMessageListener("file.open", function (e) {
+  var testFile = Cc["@mozilla.org/file/directory_service;1"]
+                   .getService(Ci.nsIDirectoryService)
+                   .QueryInterface(Ci.nsIProperties)
+                   .get("ProfD", Ci.nsIFile);
+  testFile.append("prefs.js");
+
+  sendAsyncMessage("file.opened", {
+    file: File.createFromNsIFile(testFile)
+  });
+});
diff --git a/dom/filesystem/tests/test_basic.html b/dom/filesystem/tests/test_basic.html
new file mode 100644
index 000000000..1308b9e3c
--- /dev/null
+++ b/dom/filesystem/tests/test_basic.html
@@ -0,0 +1,167 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for Directory API</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="filesystem_commons.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+
+<body>
+<script type="application/javascript;version=1.7">
+
+var directory;
+var fileList;
+
+function create_fileList(aPath) {
+  fileList = document.createElement('input');
+  fileList.setAttribute('type', 'file');
+  document.body.appendChild(fileList);
+
+  var url = SimpleTest.getTestFileURL("script_fileList.js");
+  var script = SpecialPowers.loadChromeScript(url);
+
+  function onOpened(message) {
+    SpecialPowers.wrap(fileList).mozSetDirectory(message.dir);
+    fileList.setAttribute('data-name', message.name);
+
+    fileList.getFilesAndDirectories().then(function(array) {
+      is(array.length, 1, "We want just 1 directory.");
+      ok(array[0] instanceof Directory, "We want just 1 directory.");
+
+      directory = array[0];
+      script.destroy();
+      next();
+    });
+  }
+
+  script.addMessageListener("dir.opened", onOpened);
+  script.sendAsyncMessage("dir.open", { path: aPath });
+}
+
+function test_simpleFilePicker(aPath) {
+  var url = SimpleTest.getTestFileURL("script_fileList.js");
+  var script = SpecialPowers.loadChromeScript(url);
+
+  function onOpened(message) {
+    SpecialPowers.wrap(fileList).mozSetFileArray([message.file]);
+
+    is(fileList.files.length, 1, "we want 1 element");
+    ok(fileList.files[0] instanceof File, "we want 1 file");
+    ok("webkitRelativePath" in fileList.files[0], "we have webkitRelativePath attribute");
+    is(fileList.files[0].webkitRelativePath, "", "No webkit relative path for normal filePicker");
+
+    script.destroy();
+    next();
+  }
+
+  script.addMessageListener("file.opened", onOpened);
+  script.sendAsyncMessage("file.open");
+}
+
+function test_duplicateGetFilesAndDirectories() {
+  var url = SimpleTest.getTestFileURL("script_fileList.js");
+  var script = SpecialPowers.loadChromeScript(url);
+
+  function onOpened(message) {
+    SpecialPowers.wrap(fileList).mozSetDirectory(message.dir);
+
+    var p1 = fileList.getFilesAndDirectories();
+    var p2 = fileList.getFilesAndDirectories();
+
+    isnot(p1, p2, "We create 2 different promises");
+
+    script.destroy();
+    next();
+  }
+
+  script.addMessageListener("dir.opened", onOpened);
+  script.sendAsyncMessage("dir.open", { path: 'test' });
+}
+
+function test_inputGetFiles() {
+  var url = SimpleTest.getTestFileURL("script_fileList.js");
+  var script = SpecialPowers.loadChromeScript(url);
+
+  function onOpened(message) {
+    SpecialPowers.wrap(fileList).mozSetDirectory(message.dir);
+    fileList.setAttribute('data-name', message.name);
+
+    fileList.getFilesAndDirectories()
+    .then(function(result) {
+       is(result.length, 1, "getFilesAndDirectories should return 1 element");
+       ok(result[0] instanceof Directory, "getFilesAndDirectories should return 1 directory");
+
+      return fileList.getFiles(false);
+    })
+    .then(function(result) {
+      is(result.length, 1, "getFiles should return 1 element");
+      ok(result[0] instanceof File, "getFile should return 1 file");
+      is(result[0].name, 'foo.txt', "getFiles()[0].name should be 'foo.txt'");
+      is(result[0].webkitRelativePath, fileList.dataset.name + '/foo.txt', "getFiles()[0].webkitRelativePath should be '/foo.txt'");
+
+      return fileList.getFiles(true);
+    })
+    .then(function(result) {
+      is(result.length, 2, "getFiles should return 2 elements");
+
+      function checkFile(file) {
+        ok(file instanceof File, "getFile[x] should return a file");
+        if (file.name == 'foo.txt') {
+          is(file.webkitRelativePath, fileList.dataset.name + '/foo.txt', "getFiles()[x].webkitRelativePath should be '/foo.txt'");
+        } else {
+          is(file.name, 'bar.txt', "getFiles()[x].name should be 'bar.txt'");
+          is(file.webkitRelativePath, fileList.dataset.name + '/subdir/bar.txt', "getFiles()[x].webkitRelativePath should be '/subdir/bar.txt'");
+        }
+      }
+
+      checkFile(result[0]);
+      checkFile(result[1]);
+    })
+    .then(function() {
+      script.destroy();
+      next();
+    });
+  }
+
+  script.addMessageListener("dir.opened", onOpened);
+  script.sendAsyncMessage("dir.open", { path: 'test' });
+}
+
+var tests = [
+  function() { setup_tests(next); },
+
+  function() { create_fileList('tree') },
+  function() { test_basic(directory, next); },
+  function() { test_getFilesAndDirectories(directory, true, next); },
+  function() { test_getFiles(directory, false, next); },
+  function() { test_getFiles(directory, true, next); },
+
+  function() { create_fileList('test') },
+  function() { test_getFiles_recursiveComparison(directory, next); },
+
+  function() { create_fileList('root'); },
+  function() { test_basic(directory, next); },
+  function() { test_getFilesAndDirectories(directory, false, next); },
+  function() { test_getFiles(directory, false, next); },
+
+  test_duplicateGetFilesAndDirectories,
+  test_inputGetFiles,
+  test_simpleFilePicker
+];
+
+function next() {
+  if (!tests.length) {
+    SimpleTest.finish();
+    return;
+  }
+
+  var test = tests.shift();
+  test();
+}
+
+SimpleTest.waitForExplicitFinish();
+next();
+</script>
+</body>
+</html>
diff --git a/dom/filesystem/tests/test_bug1319088.html b/dom/filesystem/tests/test_bug1319088.html
new file mode 100644
index 000000000..e0a53223f
--- /dev/null
+++ b/dom/filesystem/tests/test_bug1319088.html
@@ -0,0 +1,66 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for bug 1319088</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+
+<body>
+<input id="input" type="file"></input>
+
+<script type="application/javascript;version=1.7">
+
+function testSetup() {
+  SpecialPowers.pushPrefEnv({"set": [["dom.input.dirpicker", true],
+                                     ["dom.webkitBlink.dirPicker.enabled", true]]}, next);
+}
+
+function populateInputFile() {
+  var url = SimpleTest.getTestFileURL("script_fileList.js");
+  var script = SpecialPowers.loadChromeScript(url);
+
+  function onOpened(message) {
+    var input = document.getElementById("input");
+    SpecialPowers.wrap(input).mozSetFileArray([message.file]);
+
+    script.destroy();
+    next();
+  }
+
+  script.addMessageListener("file.opened", onOpened);
+  script.sendAsyncMessage("file.open");
+}
+
+function checkBug() {
+  var input = document.getElementById("input");
+  is(input.files[0].webkitRelativePath, "", "No relative path!");
+
+  let form = document.createElement('form');
+  form.appendChild(input);
+
+  is(input.files[0].webkitRelativePath, "", "No relative path!");
+  SimpleTest.finish();
+}
+
+var tests = [
+  testSetup,
+  populateInputFile,
+  checkBug,
+];
+
+function next() {
+  if (!tests.length) {
+    SimpleTest.finish();
+    return;
+  }
+
+  var test = tests.shift();
+  test();
+}
+
+SimpleTest.waitForExplicitFinish();
+next();
+</script>
+</body>
+</html>
diff --git a/dom/filesystem/tests/test_webkitdirectory.html b/dom/filesystem/tests/test_webkitdirectory.html
new file mode 100644
index 000000000..825f5e8fb
--- /dev/null
+++ b/dom/filesystem/tests/test_webkitdirectory.html
@@ -0,0 +1,191 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for webkitdirectory and webkitRelativePath</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+
+<body>
+<input id="inputFileWebkitDirectory" type="file" webkitdirectory></input>
+<input id="inputFileWebkitDirectoryAndDirectory" type="file" webkitdirectory allowdirs></input>
+<input id="inputFileDirectory" type="file" allowdirs></input>
+<input id="inputFileDirectoryChange" type="file" webkitdirectory></input>
+
+<script type="application/javascript;version=1.7">
+
+function populateInputFile(aInputFile) {
+  var url = SimpleTest.getTestFileURL("script_fileList.js");
+  var script = SpecialPowers.loadChromeScript(url);
+
+  var MockFilePicker = SpecialPowers.MockFilePicker;
+  MockFilePicker.init(window, "A Mock File Picker", SpecialPowers.Ci.nsIFilePicker.modeOpen);
+
+  function onOpened(message) {
+    MockFilePicker.useDirectory(message.dir);
+
+    var input = document.getElementById(aInputFile);
+    input.setAttribute('data-name', message.name);
+    input.addEventListener('change', function change() {
+      input.removeEventListener('change', change);
+      MockFilePicker.cleanup();
+      script.destroy();
+      next();
+    });
+
+    input.click();
+  }
+
+  script.addMessageListener("dir.opened", onOpened);
+  script.sendAsyncMessage("dir.open", { path: 'test' });
+}
+
+function checkFile(file, fileList, dirName) {
+  for (var i = 0; i < fileList.length; ++i) {
+    ok(fileList[i] instanceof File, "We want just files.");
+    if (fileList[i].name == file.name) {
+      is(fileList[i].webkitRelativePath, dirName + file.path, "Path matches");
+      return;
+    }
+  }
+
+  ok(false, "File not found.");
+}
+
+function test_fileList(aInputFile, aWhat) {
+  var input = document.getElementById(aInputFile);
+  var fileList = input.files;
+
+  if (aWhat == null) {
+    is(fileList, null, "We want a null fileList for " + aInputFile);
+    next();
+    return;
+  }
+
+  is(fileList.length, aWhat.length, "We want just " + aWhat.length + " elements for " + aInputFile);
+  for (var i = 0; i < aWhat.length; ++i) {
+    checkFile(aWhat[i], fileList, input.dataset.name);
+  }
+
+  next();
+}
+
+function test_webkitdirectory_attribute() {
+  var a = document.createElement("input");
+  a.setAttribute("type", "file");
+
+  ok("webkitdirectory" in a, "HTMLInputElement.webkitdirectory exists");
+
+  ok(!a.hasAttribute("webkitdirectory"), "No webkitdirectory DOM attribute by default");
+  ok(!a.webkitdirectory, "No webkitdirectory attribute by default");
+
+  a.webkitdirectory = true;
+
+  ok(a.hasAttribute("webkitdirectory"), "Webkitdirectory DOM attribute is set");
+  ok(a.webkitdirectory, "Webkitdirectory attribute is set");
+
+  next();
+}
+
+function test_changeDataWhileWorking() {
+  var url = SimpleTest.getTestFileURL("script_fileList.js");
+  var script = SpecialPowers.loadChromeScript(url);
+
+  var MockFilePicker = SpecialPowers.MockFilePicker;
+  MockFilePicker.init(window, "A Mock File Picker", SpecialPowers.Ci.nsIFilePicker.modeOpen);
+
+  // Let's start retrieving the root nsIFile object
+  new Promise(function(resolve) {
+    function onOpened(message) {
+      script.removeMessageListener("dir.opened", onOpened);
+      resolve(message.dir);
+    }
+
+    script.addMessageListener("dir.opened", onOpened);
+    script.sendAsyncMessage("dir.open", { path: 'root' });
+  })
+
+  // input.click() pointing to the root dir
+  .then(function(aDir) {
+    MockFilePicker.cleanup();
+    MockFilePicker.init(window, "A Mock File Picker", SpecialPowers.Ci.nsIFilePicker.modeOpen);
+    MockFilePicker.useDirectory(aDir);
+    var input = document.getElementById("inputFileDirectoryChange");
+    input.click();
+  })
+
+  // Before onchange, let's take the 'test' directory
+  .then(function() {
+    return new Promise(function(resolve) {
+      function onOpened(message) {
+        script.removeMessageListener("dir.opened", onOpened);
+        script.destroy();
+        resolve(message.dir);
+      }
+
+      script.addMessageListener("dir.opened", onOpened);
+      script.sendAsyncMessage("dir.open", { path: 'test' });
+    });
+  })
+
+  // Now let's click again and wait for onchange.
+  .then(function(aDir) {
+    return new Promise(function(resolve) {
+      MockFilePicker.cleanup();
+      MockFilePicker.init(window, "A Mock File Picker", SpecialPowers.Ci.nsIFilePicker.modeOpen);
+      MockFilePicker.useDirectory(aDir);
+
+      var input = document.getElementById("inputFileDirectoryChange");
+      input.addEventListener('change', function() {
+        MockFilePicker.cleanup();
+        resolve();
+      });
+
+      input.click();
+    })
+  })
+
+  .then(function() {
+    test_fileList('inputFileWebkitDirectory', testDirData);
+  });
+}
+
+function test_setup() {
+  SpecialPowers.pushPrefEnv({"set": [["dom.input.dirpicker", true],
+                                     ["dom.webkitBlink.dirPicker.enabled", true]]}, next);
+}
+
+var testDirData = [ { name: 'foo.txt', path: '/foo.txt' },
+                    { name: 'bar.txt', path: '/subdir/bar.txt' }];
+
+var tests = [
+  test_setup,
+
+  function() { populateInputFile('inputFileWebkitDirectory'); },
+  function() { populateInputFile('inputFileWebkitDirectoryAndDirectory'); },
+  function() { populateInputFile('inputFileDirectory'); },
+
+  function() { test_fileList('inputFileWebkitDirectory', testDirData) },
+  function() { test_fileList('inputFileWebkitDirectoryAndDirectory', testDirData) },
+  function() { test_fileList('inputFileDirectory', null); },
+
+  test_webkitdirectory_attribute,
+
+  test_changeDataWhileWorking,
+];
+
+function next() {
+  if (!tests.length) {
+    SimpleTest.finish();
+    return;
+  }
+
+  var test = tests.shift();
+  test();
+}
+
+SimpleTest.waitForExplicitFinish();
+next();
+</script>
+</body>
+</html>
diff --git a/dom/filesystem/tests/test_worker_basic.html b/dom/filesystem/tests/test_worker_basic.html
new file mode 100644
index 000000000..fd36faeeb
--- /dev/null
+++ b/dom/filesystem/tests/test_worker_basic.html
@@ -0,0 +1,72 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test for Directory API in workers</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="filesystem_commons.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+
+<body>
+<script type="application/javascript;version=1.7">
+
+var fileList;
+
+function create_fileList() {
+  fileList = document.createElement('input');
+  fileList.setAttribute('type', 'file');
+  document.body.appendChild(fileList);
+
+  var url = SimpleTest.getTestFileURL("script_fileList.js");
+  var script = SpecialPowers.loadChromeScript(url);
+
+  function onOpened(message) {
+    SpecialPowers.wrap(fileList).mozSetDirectory(message.dir);
+    script.destroy();
+    next();
+  }
+
+  script.addMessageListener("dir.opened", onOpened);
+  script.sendAsyncMessage("dir.open", { path: 'ProfD' });
+}
+
+function test_worker() {
+  fileList.getFilesAndDirectories().then(function(array) {
+    var worker = new Worker('worker_basic.js');
+    worker.onmessage = function(e) {
+      if (e.data.type == 'finish') {
+        next();
+        return;
+      }
+
+      if (e.data.type == 'test') {
+        ok(e.data.test, e.data.message);
+      }
+    }
+
+    worker.postMessage(array[0]);
+  });
+}
+
+var tests = [
+  function() { setup_tests(next); },
+
+  create_fileList,
+  test_worker,
+];
+
+function next() {
+  if (!tests.length) {
+    SimpleTest.finish();
+    return;
+  }
+
+  var test = tests.shift();
+  test();
+}
+
+SimpleTest.waitForExplicitFinish();
+next();
+</script>
+</body>
+</html>
diff --git a/dom/filesystem/tests/worker_basic.js b/dom/filesystem/tests/worker_basic.js
new file mode 100644
index 000000000..01df3fbd1
--- /dev/null
+++ b/dom/filesystem/tests/worker_basic.js
@@ -0,0 +1,41 @@
+importScripts('filesystem_commons.js');
+
+function finish() {
+  postMessage({ type: 'finish' });
+}
+
+function ok(a, msg) {
+  postMessage({ type: 'test', test: !!a, message: msg });
+}
+
+function is(a, b, msg) {
+  ok(a === b, msg);
+}
+
+function isnot(a, b, msg) {
+  ok(a != b, msg);
+}
+
+var tests = [
+  function() { test_basic(directory, next); },
+  function() { test_getFilesAndDirectories(directory, true, next); },
+  function() { test_getFiles(directory, false, next); },
+  function() { test_getFiles(directory, true, next); },
+];
+
+function next() {
+  if (!tests.length) {
+    finish();
+    return;
+  }
+
+  var test = tests.shift();
+  test();
+}
+
+var directory;
+
+onmessage = function(e) {
+  directory = e.data;
+  next();
+}