Add m-esr52 at 52.6.0

1 files changed, 2812 insertions, 0 deletions

diff --git a/embedding/components/webbrowserpersist/nsWebBrowserPersist.cpp b/embedding/components/webbrowserpersist/nsWebBrowserPersist.cpp
new file mode 100644
index 000000000..de85a59bb
--- /dev/null
+++ b/embedding/components/webbrowserpersist/nsWebBrowserPersist.cpp
@@ -0,0 +1,2812 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * 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/ArrayUtils.h"
+
+#include "nspr.h"
+
+#include "nsIFileStreams.h"       // New Necko file streams
+#include <algorithm>
+
+#include "nsAutoPtr.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIPrivateBrowsingChannel.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIComponentRegistrar.h"
+#include "nsIStorageStream.h"
+#include "nsISeekableStream.h"
+#include "nsIHttpChannel.h"
+#include "nsIHttpChannelInternal.h"
+#include "nsIEncodedChannel.h"
+#include "nsIUploadChannel.h"
+#include "nsICacheInfoChannel.h"
+#include "nsIFileChannel.h"
+#include "nsEscape.h"
+#include "nsUnicharUtils.h"
+#include "nsIStringEnumerator.h"
+#include "nsCRT.h"
+#include "nsContentCID.h"
+#include "nsStreamUtils.h"
+
+#include "nsCExternalHandlerService.h"
+
+#include "nsIURL.h"
+#include "nsIFileURL.h"
+#include "nsIWebProgressListener.h"
+#include "nsIAuthPrompt.h"
+#include "nsIPrompt.h"
+#include "nsISHEntry.h"
+#include "nsIWebPageDescriptor.h"
+#include "nsIFormControl.h"
+#include "nsContentUtils.h"
+
+#include "nsIImageLoadingContent.h"
+
+#include "ftpCore.h"
+#include "nsITransport.h"
+#include "nsISocketTransport.h"
+#include "nsIStringBundle.h"
+#include "nsIProtocolHandler.h"
+
+#include "nsIWebBrowserPersistable.h"
+#include "nsWebBrowserPersist.h"
+#include "WebBrowserPersistLocalDocument.h"
+
+#include "nsIContent.h"
+#include "nsIMIMEInfo.h"
+#include "mozilla/dom/HTMLInputElement.h"
+#include "mozilla/dom/HTMLSharedElement.h"
+#include "mozilla/dom/HTMLSharedObjectElement.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+// Buffer file writes in 32kb chunks
+#define BUFFERED_OUTPUT_SIZE (1024 * 32)
+
+struct nsWebBrowserPersist::WalkData
+{
+    nsCOMPtr<nsIWebBrowserPersistDocument> mDocument;
+    nsCOMPtr<nsIURI> mFile;
+    nsCOMPtr<nsIURI> mDataPath;
+};
+
+// Information about a DOM document
+struct nsWebBrowserPersist::DocData
+{
+    nsCOMPtr<nsIURI> mBaseURI;
+    nsCOMPtr<nsIWebBrowserPersistDocument> mDocument;
+    nsCOMPtr<nsIURI> mFile;
+    nsCString mCharset;
+};
+
+// Information about a URI
+struct nsWebBrowserPersist::URIData
+{
+    bool mNeedsPersisting;
+    bool mSaved;
+    bool mIsSubFrame;
+    bool mDataPathIsRelative;
+    bool mNeedsFixup;
+    nsString mFilename;
+    nsString mSubFrameExt;
+    nsCOMPtr<nsIURI> mFile;
+    nsCOMPtr<nsIURI> mDataPath;
+    nsCOMPtr<nsIURI> mRelativeDocumentURI;
+    nsCString mRelativePathToData;
+    nsCString mCharset;
+
+    nsresult GetLocalURI(nsIURI *targetBaseURI, nsCString& aSpecOut);
+};
+
+// Information about the output stream
+struct nsWebBrowserPersist::OutputData
+{
+    nsCOMPtr<nsIURI> mFile;
+    nsCOMPtr<nsIURI> mOriginalLocation;
+    nsCOMPtr<nsIOutputStream> mStream;
+    int64_t mSelfProgress;
+    int64_t mSelfProgressMax;
+    bool mCalcFileExt;
+
+    OutputData(nsIURI *aFile, nsIURI *aOriginalLocation, bool aCalcFileExt) :
+        mFile(aFile),
+        mOriginalLocation(aOriginalLocation),
+        mSelfProgress(0),
+        mSelfProgressMax(10000),
+        mCalcFileExt(aCalcFileExt)
+    {
+    }
+    ~OutputData()
+    {
+        if (mStream)
+        {
+            mStream->Close();
+        }
+    }
+};
+
+struct nsWebBrowserPersist::UploadData
+{
+    nsCOMPtr<nsIURI> mFile;
+    int64_t mSelfProgress;
+    int64_t mSelfProgressMax;
+
+    explicit UploadData(nsIURI *aFile) :
+        mFile(aFile),
+        mSelfProgress(0),
+        mSelfProgressMax(10000)
+    {
+    }
+};
+
+struct nsWebBrowserPersist::CleanupData
+{
+    nsCOMPtr<nsIFile> mFile;
+    // Snapshot of what the file actually is at the time of creation so that if
+    // it transmutes into something else later on it can be ignored. For example,
+    // catch files that turn into dirs or vice versa.
+    bool mIsDirectory;
+};
+
+class nsWebBrowserPersist::OnWalk final
+    : public nsIWebBrowserPersistResourceVisitor
+{
+public:
+    OnWalk(nsWebBrowserPersist* aParent, nsIURI* aFile, nsIFile* aDataPath)
+    : mParent(aParent)
+    , mFile(aFile)
+    , mDataPath(aDataPath)
+    { }
+
+    NS_DECL_NSIWEBBROWSERPERSISTRESOURCEVISITOR
+    NS_DECL_ISUPPORTS
+private:
+    RefPtr<nsWebBrowserPersist> mParent;
+    nsCOMPtr<nsIURI> mFile;
+    nsCOMPtr<nsIFile> mDataPath;
+
+    virtual ~OnWalk() { }
+};
+
+NS_IMPL_ISUPPORTS(nsWebBrowserPersist::OnWalk,
+                  nsIWebBrowserPersistResourceVisitor)
+
+class nsWebBrowserPersist::OnWrite final
+    : public nsIWebBrowserPersistWriteCompletion
+{
+public:
+    OnWrite(nsWebBrowserPersist* aParent,
+            nsIURI* aFile,
+            nsIFile* aLocalFile)
+    : mParent(aParent)
+    , mFile(aFile)
+    , mLocalFile(aLocalFile)
+    { }
+
+    NS_DECL_NSIWEBBROWSERPERSISTWRITECOMPLETION
+    NS_DECL_ISUPPORTS
+private:
+    RefPtr<nsWebBrowserPersist> mParent;
+    nsCOMPtr<nsIURI> mFile;
+    nsCOMPtr<nsIFile> mLocalFile;
+
+    virtual ~OnWrite() { }
+};
+
+NS_IMPL_ISUPPORTS(nsWebBrowserPersist::OnWrite,
+                  nsIWebBrowserPersistWriteCompletion)
+
+class nsWebBrowserPersist::FlatURIMap final
+    : public nsIWebBrowserPersistURIMap
+{
+public:
+    explicit FlatURIMap(const nsACString& aTargetBase)
+    : mTargetBase(aTargetBase) { }
+
+    void Add(const nsACString& aMapFrom, const nsACString& aMapTo) {
+        mMapFrom.AppendElement(aMapFrom);
+        mMapTo.AppendElement(aMapTo);
+    }
+
+    NS_DECL_NSIWEBBROWSERPERSISTURIMAP
+    NS_DECL_ISUPPORTS
+
+private:
+    nsTArray<nsCString> mMapFrom;
+    nsTArray<nsCString> mMapTo;
+    nsCString mTargetBase;
+
+    virtual ~FlatURIMap() { }
+};
+
+NS_IMPL_ISUPPORTS(nsWebBrowserPersist::FlatURIMap, nsIWebBrowserPersistURIMap)
+
+NS_IMETHODIMP
+nsWebBrowserPersist::FlatURIMap::GetNumMappedURIs(uint32_t* aNum)
+{
+    MOZ_ASSERT(mMapFrom.Length() == mMapTo.Length());
+    *aNum = mMapTo.Length();
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserPersist::FlatURIMap::GetTargetBaseURI(nsACString& aTargetBase)
+{
+    aTargetBase = mTargetBase;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWebBrowserPersist::FlatURIMap::GetURIMapping(uint32_t aIndex,
+                                      nsACString& aMapFrom,
+                                      nsACString& aMapTo)
+{
+    MOZ_ASSERT(mMapFrom.Length() == mMapTo.Length());
+    if (aIndex >= mMapTo.Length()) {
+        return NS_ERROR_INVALID_ARG;
+    }
+    aMapFrom = mMapFrom[aIndex];
+    aMapTo = mMapTo[aIndex];
+    return NS_OK;
+}
+
+
+// Maximum file length constant. The max file name length is
+// volume / server dependent but it is difficult to obtain
+// that information. Instead this constant is a reasonable value that
+// modern systems should able to cope with.
+const uint32_t kDefaultMaxFilenameLength = 64;
+
+// Default flags for persistence
+const uint32_t kDefaultPersistFlags =
+    nsIWebBrowserPersist::PERSIST_FLAGS_NO_CONVERSION |
+    nsIWebBrowserPersist::PERSIST_FLAGS_REPLACE_EXISTING_FILES;
+
+// String bundle where error messages come from
+const char *kWebBrowserPersistStringBundle =
+    "chrome://global/locale/nsWebBrowserPersist.properties";
+
+nsWebBrowserPersist::nsWebBrowserPersist() :
+    mCurrentDataPathIsRelative(false),
+    mCurrentThingsToPersist(0),
+    mFirstAndOnlyUse(true),
+    mSavingDocument(false),
+    mCancel(false),
+    mCompleted(false),
+    mStartSaving(false),
+    mReplaceExisting(true),
+    mSerializingOutput(false),
+    mIsPrivate(false),
+    mPersistFlags(kDefaultPersistFlags),
+    mPersistResult(NS_OK),
+    mTotalCurrentProgress(0),
+    mTotalMaxProgress(0),
+    mWrapColumn(72),
+    mEncodingFlags(0)
+{
+}
+
+nsWebBrowserPersist::~nsWebBrowserPersist()
+{
+    Cleanup();
+}
+
+//*****************************************************************************
+// nsWebBrowserPersist::nsISupports
+//*****************************************************************************
+
+NS_IMPL_ADDREF(nsWebBrowserPersist)
+NS_IMPL_RELEASE(nsWebBrowserPersist)
+
+NS_INTERFACE_MAP_BEGIN(nsWebBrowserPersist)
+    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIWebBrowserPersist)
+    NS_INTERFACE_MAP_ENTRY(nsIWebBrowserPersist)
+    NS_INTERFACE_MAP_ENTRY(nsICancelable)
+    NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)
+    NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
+    NS_INTERFACE_MAP_ENTRY(nsIStreamListener)
+    NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
+    NS_INTERFACE_MAP_ENTRY(nsIProgressEventSink)
+NS_INTERFACE_MAP_END
+
+
+//*****************************************************************************
+// nsWebBrowserPersist::nsIInterfaceRequestor
+//*****************************************************************************
+
+NS_IMETHODIMP nsWebBrowserPersist::GetInterface(const nsIID & aIID, void **aIFace)
+{
+    NS_ENSURE_ARG_POINTER(aIFace);
+
+    *aIFace = nullptr;
+
+    nsresult rv = QueryInterface(aIID, aIFace);
+    if (NS_SUCCEEDED(rv))
+    {
+        return rv;
+    }
+
+    if (mProgressListener && (aIID.Equals(NS_GET_IID(nsIAuthPrompt))
+                             || aIID.Equals(NS_GET_IID(nsIPrompt))))
+    {
+        mProgressListener->QueryInterface(aIID, aIFace);
+        if (*aIFace)
+            return NS_OK;
+    }
+
+    nsCOMPtr<nsIInterfaceRequestor> req = do_QueryInterface(mProgressListener);
+    if (req)
+    {
+        return req->GetInterface(aIID, aIFace);
+    }
+
+    return NS_ERROR_NO_INTERFACE;
+}
+
+
+//*****************************************************************************
+// nsWebBrowserPersist::nsIWebBrowserPersist
+//*****************************************************************************
+
+NS_IMETHODIMP nsWebBrowserPersist::GetPersistFlags(uint32_t *aPersistFlags)
+{
+    NS_ENSURE_ARG_POINTER(aPersistFlags);
+    *aPersistFlags = mPersistFlags;
+    return NS_OK;
+}
+NS_IMETHODIMP nsWebBrowserPersist::SetPersistFlags(uint32_t aPersistFlags)
+{
+    mPersistFlags = aPersistFlags;
+    mReplaceExisting = (mPersistFlags & PERSIST_FLAGS_REPLACE_EXISTING_FILES) ? true : false;
+    mSerializingOutput = (mPersistFlags & PERSIST_FLAGS_SERIALIZE_OUTPUT) ? true : false;
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsWebBrowserPersist::GetCurrentState(uint32_t *aCurrentState)
+{
+    NS_ENSURE_ARG_POINTER(aCurrentState);
+    if (mCompleted)
+    {
+        *aCurrentState = PERSIST_STATE_FINISHED;
+    }
+    else if (mFirstAndOnlyUse)
+    {
+        *aCurrentState = PERSIST_STATE_SAVING;
+    }
+    else
+    {
+        *aCurrentState = PERSIST_STATE_READY;
+    }
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsWebBrowserPersist::GetResult(nsresult *aResult)
+{
+    NS_ENSURE_ARG_POINTER(aResult);
+    *aResult = mPersistResult;
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsWebBrowserPersist::GetProgressListener(
+    nsIWebProgressListener * *aProgressListener)
+{
+    NS_ENSURE_ARG_POINTER(aProgressListener);
+    *aProgressListener = mProgressListener;
+    NS_IF_ADDREF(*aProgressListener);
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsWebBrowserPersist::SetProgressListener(
+    nsIWebProgressListener * aProgressListener)
+{
+    mProgressListener = aProgressListener;
+    mProgressListener2 = do_QueryInterface(aProgressListener);
+    mEventSink = do_GetInterface(aProgressListener);
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsWebBrowserPersist::SaveURI(
+    nsIURI *aURI, nsISupports *aCacheKey,
+    nsIURI *aReferrer, uint32_t aReferrerPolicy,
+    nsIInputStream *aPostData, const char *aExtraHeaders,
+    nsISupports *aFile, nsILoadContext* aPrivacyContext)
+{
+    return SavePrivacyAwareURI(aURI, aCacheKey, aReferrer, aReferrerPolicy,
+                               aPostData, aExtraHeaders, aFile,
+                               aPrivacyContext && aPrivacyContext->UsePrivateBrowsing());
+}
+
+NS_IMETHODIMP nsWebBrowserPersist::SavePrivacyAwareURI(
+    nsIURI *aURI, nsISupports *aCacheKey,
+    nsIURI *aReferrer, uint32_t aReferrerPolicy,
+    nsIInputStream *aPostData, const char *aExtraHeaders, 
+    nsISupports *aFile, bool aIsPrivate)
+{
+    NS_ENSURE_TRUE(mFirstAndOnlyUse, NS_ERROR_FAILURE);
+    mFirstAndOnlyUse = false; // Stop people from reusing this object!
+
+    nsCOMPtr<nsIURI> fileAsURI;
+    nsresult rv;
+    rv = GetValidURIFromObject(aFile, getter_AddRefs(fileAsURI));
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_INVALID_ARG);
+
+    // SaveURI doesn't like broken uris.
+    mPersistFlags |= PERSIST_FLAGS_FAIL_ON_BROKEN_LINKS;
+    rv = SaveURIInternal(aURI, aCacheKey, aReferrer, aReferrerPolicy,
+                         aPostData, aExtraHeaders, fileAsURI, false, aIsPrivate);
+    return NS_FAILED(rv) ? rv : NS_OK;
+}
+
+NS_IMETHODIMP nsWebBrowserPersist::SaveChannel(
+    nsIChannel *aChannel, nsISupports *aFile)
+{
+    NS_ENSURE_TRUE(mFirstAndOnlyUse, NS_ERROR_FAILURE);
+    mFirstAndOnlyUse = false; // Stop people from reusing this object!
+
+    nsCOMPtr<nsIURI> fileAsURI;
+    nsresult rv;
+    rv = GetValidURIFromObject(aFile, getter_AddRefs(fileAsURI));
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_INVALID_ARG);
+
+    rv = aChannel->GetURI(getter_AddRefs(mURI));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // SaveURI doesn't like broken uris.
+    mPersistFlags |= PERSIST_FLAGS_FAIL_ON_BROKEN_LINKS;
+    rv = SaveChannelInternal(aChannel, fileAsURI, false);
+    return NS_FAILED(rv) ? rv : NS_OK;
+}
+
+
+NS_IMETHODIMP nsWebBrowserPersist::SaveDocument(
+    nsISupports *aDocument, nsISupports *aFile, nsISupports *aDataPath,
+    const char *aOutputContentType, uint32_t aEncodingFlags, uint32_t aWrapColumn)
+{
+    NS_ENSURE_TRUE(mFirstAndOnlyUse, NS_ERROR_FAILURE);
+    mFirstAndOnlyUse = false; // Stop people from reusing this object!
+
+    // We need a STATE_IS_NETWORK start/stop pair to bracket the
+    // notification callbacks.  For a whole document we generate those
+    // here and in EndDownload(), but for the single-request methods
+    // that's done in On{Start,Stop}Request instead.
+    mSavingDocument = true;
+
+    NS_ENSURE_ARG_POINTER(aDocument);
+    NS_ENSURE_ARG_POINTER(aFile);
+
+    nsCOMPtr<nsIURI> fileAsURI;
+    nsCOMPtr<nsIURI> datapathAsURI;
+    nsresult rv;
+
+    rv = GetValidURIFromObject(aFile, getter_AddRefs(fileAsURI));
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_INVALID_ARG);
+    if (aDataPath)
+    {
+        rv = GetValidURIFromObject(aDataPath, getter_AddRefs(datapathAsURI));
+        NS_ENSURE_SUCCESS(rv, NS_ERROR_INVALID_ARG);
+    }
+
+    mWrapColumn = aWrapColumn;
+    mEncodingFlags = aEncodingFlags;
+
+    if (aOutputContentType)
+    {
+        mContentType.AssignASCII(aOutputContentType);
+    }
+
+    // State start notification
+    if (mProgressListener) {
+        mProgressListener->OnStateChange(nullptr, nullptr,
+            nsIWebProgressListener::STATE_START
+            | nsIWebProgressListener::STATE_IS_NETWORK, NS_OK);
+    }
+
+    nsCOMPtr<nsIWebBrowserPersistDocument> doc = do_QueryInterface(aDocument);
+    if (!doc) {
+        nsCOMPtr<nsIDocument> localDoc = do_QueryInterface(aDocument);
+        if (localDoc) {
+            doc = new mozilla::WebBrowserPersistLocalDocument(localDoc);
+        } else {
+            rv = NS_ERROR_NO_INTERFACE;
+        }
+    }
+    if (doc) {
+        rv = SaveDocumentInternal(doc, fileAsURI, datapathAsURI);
+    }
+    if (NS_FAILED(rv)) {
+        SendErrorStatusChange(true, rv, nullptr, mURI);
+        EndDownload(rv);
+    }
+    return rv;
+}
+
+NS_IMETHODIMP nsWebBrowserPersist::Cancel(nsresult aReason)
+{
+    mCancel = true;
+    EndDownload(aReason);
+    return NS_OK;
+}
+
+
+NS_IMETHODIMP nsWebBrowserPersist::CancelSave()
+{
+    return Cancel(NS_BINDING_ABORTED);
+}
+
+
+nsresult
+nsWebBrowserPersist::StartUpload(nsIStorageStream *storStream,
+    nsIURI *aDestinationURI, const nsACString &aContentType)
+{
+     // setup the upload channel if the destination is not local
+    nsCOMPtr<nsIInputStream> inputstream;
+    nsresult rv = storStream->NewInputStream(0, getter_AddRefs(inputstream));
+    NS_ENSURE_TRUE(inputstream, NS_ERROR_FAILURE);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+    return StartUpload(inputstream, aDestinationURI, aContentType);
+}
+
+nsresult
+nsWebBrowserPersist::StartUpload(nsIInputStream *aInputStream,
+    nsIURI *aDestinationURI, const nsACString &aContentType)
+{
+    nsCOMPtr<nsIChannel> destChannel;
+    CreateChannelFromURI(aDestinationURI, getter_AddRefs(destChannel));
+    nsCOMPtr<nsIUploadChannel> uploadChannel(do_QueryInterface(destChannel));
+    NS_ENSURE_TRUE(uploadChannel, NS_ERROR_FAILURE);
+
+    // Set the upload stream
+    // NOTE: ALL data must be available in "inputstream"
+    nsresult rv = uploadChannel->SetUploadStream(aInputStream, aContentType, -1);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+    rv = destChannel->AsyncOpen2(this);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+    // add this to the upload list
+    nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(destChannel);
+    mUploadList.Put(keyPtr, new UploadData(aDestinationURI));
+
+    return NS_OK;
+}
+
+void
+nsWebBrowserPersist::SerializeNextFile()
+{
+    nsresult rv = NS_OK;
+    MOZ_ASSERT(mWalkStack.Length() == 0);
+
+    // First, handle gathered URIs.
+    // Count how many URIs in the URI map require persisting
+    uint32_t urisToPersist = 0;
+    if (mURIMap.Count() > 0) {
+        // This is potentially O(n^2), when taking into account the
+        // number of times this method is called.  If it becomes a
+        // bottleneck, the count of not-yet-persisted URIs could be
+        // maintained separately.
+        for (auto iter = mURIMap.Iter(); !iter.Done(); iter.Next()) {
+            URIData *data = iter.UserData();
+            if (data->mNeedsPersisting && !data->mSaved) {
+                urisToPersist++;
+            }
+        }
+    }
+
+    if (urisToPersist > 0) {
+        // Persist each file in the uri map. The document(s)
+        // will be saved after the last one of these is saved.
+        for (auto iter = mURIMap.Iter(); !iter.Done(); iter.Next()) {
+            URIData *data = iter.UserData();
+
+            if (!data->mNeedsPersisting || data->mSaved) {
+                continue;
+            }
+
+            nsresult rv;
+
+            // Create a URI from the key.
+            nsCOMPtr<nsIURI> uri;
+            rv = NS_NewURI(getter_AddRefs(uri), iter.Key(),
+                           data->mCharset.get());
+            if (NS_WARN_IF(NS_FAILED(rv))) {
+                break;
+            }
+
+            // Make a URI to save the data to.
+            nsCOMPtr<nsIURI> fileAsURI;
+            rv = data->mDataPath->Clone(getter_AddRefs(fileAsURI));
+            if (NS_WARN_IF(NS_FAILED(rv))) {
+                break;
+            }
+            rv = AppendPathToURI(fileAsURI, data->mFilename);
+            if (NS_WARN_IF(NS_FAILED(rv))) {
+                break;
+            }
+
+            // The Referrer Policy doesn't matter here since the referrer is
+            // nullptr.
+            rv = SaveURIInternal(uri, nullptr, nullptr,
+                                 mozilla::net::RP_Default, nullptr, nullptr,
+                                 fileAsURI, true, mIsPrivate);
+            // If SaveURIInternal fails, then it will have called EndDownload,
+            // which means that |data| is no longer valid memory. We MUST bail.
+            if (NS_WARN_IF(NS_FAILED(rv))) {
+                break;
+            }
+
+            if (rv == NS_OK) {
+                // Store the actual object because once it's persisted this
+                // will be fixed up with the right file extension.
+                data->mFile = fileAsURI;
+                data->mSaved = true;
+            } else {
+                data->mNeedsFixup = false;
+            }
+
+            if (mSerializingOutput) {
+                break;
+            }
+        }
+    }
+
+    // If there are downloads happening, wait until they're done; the
+    // OnStopRequest handler will call this method again.
+    if (mOutputMap.Count() > 0) {
+        return;
+    }
+
+    // If serializing, also wait until last upload is done.
+    if (mSerializingOutput && mUploadList.Count() > 0) {
+        return;
+    }
+
+    // If there are also no more documents, then we're done.
+    if (mDocList.Length() == 0) {
+        // ...or not quite done, if there are still uploads.
+        if (mUploadList.Count() > 0) {
+            return;
+        }
+        // Finish and clean things up.  Defer this because the caller
+        // may have been expecting to use the listeners that that
+        // method will clear.
+        NS_DispatchToCurrentThread(NewRunnableMethod(this,
+            &nsWebBrowserPersist::FinishDownload));
+        return;
+    }
+
+    // There are no URIs to save, so just save the next document.
+    mStartSaving = true;
+    mozilla::UniquePtr<DocData> docData(mDocList.ElementAt(0));
+    mDocList.RemoveElementAt(0); // O(n^2) but probably doesn't matter.
+    MOZ_ASSERT(docData);
+    if (!docData) {
+        EndDownload(NS_ERROR_FAILURE);
+        return;
+    }
+
+    mCurrentBaseURI = docData->mBaseURI;
+    mCurrentCharset = docData->mCharset;
+    mTargetBaseURI = docData->mFile;
+
+    // Save the document, fixing it up with the new URIs as we do
+
+    nsAutoCString targetBaseSpec;
+    if (mTargetBaseURI) {
+        rv = mTargetBaseURI->GetSpec(targetBaseSpec);
+        if (NS_FAILED(rv)) {
+            SendErrorStatusChange(true, rv, nullptr, nullptr);
+            EndDownload(rv);
+            return;
+        }
+    }
+
+    // mFlatURIMap must be rebuilt each time through SerializeNextFile, as
+    // mTargetBaseURI is used to create the relative URLs and will be different
+    // with each serialized document.
+    RefPtr<FlatURIMap> flatMap = new FlatURIMap(targetBaseSpec);
+    for (auto iter = mURIMap.Iter(); !iter.Done(); iter.Next()) {
+        nsAutoCString mapTo;
+        nsresult rv = iter.UserData()->GetLocalURI(mTargetBaseURI, mapTo);
+        if (NS_SUCCEEDED(rv) || !mapTo.IsVoid()) {
+            flatMap->Add(iter.Key(), mapTo);
+        }
+    }
+    mFlatURIMap = flatMap.forget();
+
+    nsCOMPtr<nsIFile> localFile;
+    GetLocalFileFromURI(docData->mFile, getter_AddRefs(localFile));
+    if (localFile) {
+        // if we're not replacing an existing file but the file
+        // exists, something is wrong
+        bool fileExists = false;
+        rv = localFile->Exists(&fileExists);
+        if (NS_SUCCEEDED(rv) && !mReplaceExisting && fileExists) {
+            rv = NS_ERROR_FILE_ALREADY_EXISTS;
+        }
+        if (NS_FAILED(rv)) {
+            SendErrorStatusChange(false, rv, nullptr, docData->mFile);
+            EndDownload(rv);
+            return;
+        }
+    }
+    nsCOMPtr<nsIOutputStream> outputStream;
+    rv = MakeOutputStream(docData->mFile, getter_AddRefs(outputStream));
+    if (NS_SUCCEEDED(rv) && !outputStream) {
+        rv = NS_ERROR_FAILURE;
+    }
+    if (NS_FAILED(rv)) {
+        SendErrorStatusChange(false, rv, nullptr, docData->mFile);
+        EndDownload(rv);
+        return;
+    }
+
+    RefPtr<OnWrite> finish = new OnWrite(this, docData->mFile, localFile);
+    rv = docData->mDocument->WriteContent(outputStream,
+                                          mFlatURIMap,
+                                          NS_ConvertUTF16toUTF8(mContentType),
+                                          mEncodingFlags,
+                                          mWrapColumn,
+                                          finish);
+    if (NS_FAILED(rv)) {
+        SendErrorStatusChange(false, rv, nullptr, docData->mFile);
+        EndDownload(rv);
+    }
+}
+
+NS_IMETHODIMP
+nsWebBrowserPersist::OnWrite::OnFinish(nsIWebBrowserPersistDocument* aDoc,
+                                       nsIOutputStream *aStream,
+                                       const nsACString& aContentType,
+                                       nsresult aStatus)
+{
+    nsresult rv = aStatus;
+
+    if (NS_FAILED(rv)) {
+        mParent->SendErrorStatusChange(false, rv, nullptr, mFile);
+        mParent->EndDownload(rv);
+        return NS_OK;
+    }
+    if (!mLocalFile) {
+        nsCOMPtr<nsIStorageStream> storStream(do_QueryInterface(aStream));
+        if (storStream) {
+            aStream->Close();
+            rv = mParent->StartUpload(storStream, mFile, aContentType);
+            if (NS_FAILED(rv)) {
+                mParent->SendErrorStatusChange(false, rv, nullptr, mFile);
+                mParent->EndDownload(rv);
+            }
+            // Either we failed and we're done, or we're uploading and
+            // the OnStopRequest callback is responsible for the next
+            // SerializeNextFile().
+            return NS_OK;
+        }
+    }
+    NS_DispatchToCurrentThread(NewRunnableMethod(mParent,
+        &nsWebBrowserPersist::SerializeNextFile));
+    return NS_OK;
+}
+
+//*****************************************************************************
+// nsWebBrowserPersist::nsIRequestObserver
+//*****************************************************************************
+
+NS_IMETHODIMP nsWebBrowserPersist::OnStartRequest(
+    nsIRequest* request, nsISupports *ctxt)
+{
+    if (mProgressListener)
+    {
+        uint32_t stateFlags = nsIWebProgressListener::STATE_START |
+                              nsIWebProgressListener::STATE_IS_REQUEST;
+        if (!mSavingDocument) {
+            stateFlags |= nsIWebProgressListener::STATE_IS_NETWORK;
+        }
+        mProgressListener->OnStateChange(nullptr, request, stateFlags, NS_OK);
+    }
+
+    nsCOMPtr<nsIChannel> channel = do_QueryInterface(request);
+    NS_ENSURE_TRUE(channel, NS_ERROR_FAILURE);
+
+    nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(request);
+    OutputData *data = mOutputMap.Get(keyPtr);
+
+    // NOTE: This code uses the channel as a hash key so it will not
+    //       recognize redirected channels because the key is not the same.
+    //       When that happens we remove and add the data entry to use the
+    //       new channel as the hash key.
+    if (!data)
+    {
+        UploadData *upData = mUploadList.Get(keyPtr);
+        if (!upData)
+        {
+            // Redirect? Try and fixup the output table
+            nsresult rv = FixRedirectedChannelEntry(channel);
+            NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+            // Should be able to find the data after fixup unless redirects
+            // are disabled.
+            data = mOutputMap.Get(keyPtr);
+            if (!data)
+            {
+                return NS_ERROR_FAILURE;
+            }
+        }
+    }
+
+    if (data && data->mFile)
+    {
+        // If PERSIST_FLAGS_AUTODETECT_APPLY_CONVERSION is set in mPersistFlags,
+        // try to determine whether this channel needs to apply Content-Encoding
+        // conversions.
+        NS_ASSERTION(!((mPersistFlags & PERSIST_FLAGS_AUTODETECT_APPLY_CONVERSION) &&
+                      (mPersistFlags & PERSIST_FLAGS_NO_CONVERSION)),
+                     "Conflict in persist flags: both AUTODETECT and NO_CONVERSION set");
+        if (mPersistFlags & PERSIST_FLAGS_AUTODETECT_APPLY_CONVERSION)
+            SetApplyConversionIfNeeded(channel);
+
+        if (data->mCalcFileExt && !(mPersistFlags & PERSIST_FLAGS_DONT_CHANGE_FILENAMES))
+        {
+            // this is the first point at which the server can tell us the mimetype
+            CalculateAndAppendFileExt(data->mFile, channel, data->mOriginalLocation);
+
+            // now make filename conformant and unique
+            CalculateUniqueFilename(data->mFile);
+        }
+
+        // compare uris and bail before we add to output map if they are equal
+        bool isEqual = false;
+        if (NS_SUCCEEDED(data->mFile->Equals(data->mOriginalLocation, &isEqual))
+            && isEqual)
+        {
+            // remove from output map
+            mOutputMap.Remove(keyPtr);
+
+            // cancel; we don't need to know any more
+            // stop request will get called
+            request->Cancel(NS_BINDING_ABORTED);
+        }
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsWebBrowserPersist::OnStopRequest(
+    nsIRequest* request, nsISupports *ctxt, nsresult status)
+{
+    nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(request);
+    OutputData *data = mOutputMap.Get(keyPtr);
+    if (data) {
+        if (NS_SUCCEEDED(mPersistResult) && NS_FAILED(status)) {
+            SendErrorStatusChange(true, status, request, data->mFile);
+        }
+
+        // This will automatically close the output stream
+        mOutputMap.Remove(keyPtr);
+    } else {
+        // if we didn't find the data in mOutputMap, try mUploadList
+        UploadData *upData = mUploadList.Get(keyPtr);
+        if (upData) {
+            mUploadList.Remove(keyPtr);
+        }
+    }
+
+    // Do more work.
+    SerializeNextFile();
+
+    if (mProgressListener) {
+        uint32_t stateFlags = nsIWebProgressListener::STATE_STOP |
+                              nsIWebProgressListener::STATE_IS_REQUEST;
+        if (!mSavingDocument) {
+            stateFlags |= nsIWebProgressListener::STATE_IS_NETWORK;
+        }
+        mProgressListener->OnStateChange(nullptr, request, stateFlags, status);
+    }
+
+    return NS_OK;
+}
+
+//*****************************************************************************
+// nsWebBrowserPersist::nsIStreamListener
+//*****************************************************************************
+
+NS_IMETHODIMP
+nsWebBrowserPersist::OnDataAvailable(
+    nsIRequest* request, nsISupports *aContext, nsIInputStream *aIStream,
+    uint64_t aOffset, uint32_t aLength)
+{
+    bool cancel = mCancel;
+    if (!cancel)
+    {
+        nsresult rv = NS_OK;
+        uint32_t bytesRemaining = aLength;
+
+        nsCOMPtr<nsIChannel> channel = do_QueryInterface(request);
+        NS_ENSURE_TRUE(channel, NS_ERROR_FAILURE);
+
+        nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(request);
+        OutputData *data = mOutputMap.Get(keyPtr);
+        if (!data) {
+            // might be uploadData; consume necko's buffer and bail...
+            uint32_t n;
+            return aIStream->ReadSegments(NS_DiscardSegment, nullptr, aLength, &n);
+        }
+
+        bool readError = true;
+
+        // Make the output stream
+        if (!data->mStream)
+        {
+            rv = MakeOutputStream(data->mFile, getter_AddRefs(data->mStream));
+            if (NS_FAILED(rv))
+            {
+                readError = false;
+                cancel = true;
+            }
+        }
+
+        // Read data from the input and write to the output
+        char buffer[8192];
+        uint32_t bytesRead;
+        while (!cancel && bytesRemaining)
+        {
+            readError = true;
+            rv = aIStream->Read(buffer,
+                                std::min(uint32_t(sizeof(buffer)), bytesRemaining),
+                                &bytesRead);
+            if (NS_SUCCEEDED(rv))
+            {
+                readError = false;
+                // Write out the data until something goes wrong, or, it is
+                // all written.  We loop because for some errors (e.g., disk
+                // full), we get NS_OK with some bytes written, then an error.
+                // So, we want to write again in that case to get the actual
+                // error code.
+                const char *bufPtr = buffer; // Where to write from.
+                while (NS_SUCCEEDED(rv) && bytesRead)
+                {
+                    uint32_t bytesWritten = 0;
+                    rv = data->mStream->Write(bufPtr, bytesRead, &bytesWritten);
+                    if (NS_SUCCEEDED(rv))
+                    {
+                        bytesRead -= bytesWritten;
+                        bufPtr += bytesWritten;
+                        bytesRemaining -= bytesWritten;
+                        // Force an error if (for some reason) we get NS_OK but
+                        // no bytes written.
+                        if (!bytesWritten)
+                        {
+                            rv = NS_ERROR_FAILURE;
+                            cancel = true;
+                        }
+                    }
+                    else
+                    {
+                        // Disaster - can't write out the bytes - disk full / permission?
+                        cancel = true;
+                    }
+                }
+            }
+            else
+            {
+                // Disaster - can't read the bytes - broken link / file error?
+                cancel = true;
+            }
+        }
+
+        int64_t channelContentLength = -1;
+        if (!cancel &&
+            NS_SUCCEEDED(channel->GetContentLength(&channelContentLength)))
+        {
+            // if we get -1 at this point, we didn't get content-length header
+            // assume that we got all of the data and push what we have;
+            // that's the best we can do now
+            if ((-1 == channelContentLength) ||
+                ((channelContentLength - (aOffset + aLength)) == 0))
+            {
+                NS_WARNING_ASSERTION(
+                    channelContentLength != -1,
+                    "nsWebBrowserPersist::OnDataAvailable() no content length "
+                    "header, pushing what we have");
+                // we're done with this pass; see if we need to do upload
+                nsAutoCString contentType;
+                channel->GetContentType(contentType);
+                // if we don't have the right type of output stream then it's a local file
+                nsCOMPtr<nsIStorageStream> storStream(do_QueryInterface(data->mStream));
+                if (storStream)
+                {
+                    data->mStream->Close();
+                    data->mStream = nullptr; // null out stream so we don't close it later
+                    rv = StartUpload(storStream, data->mFile, contentType);
+                    if (NS_FAILED(rv))
+                    {
+                        readError = false;
+                        cancel = true;
+                    }
+                }
+            }
+        }
+
+        // Notify listener if an error occurred.
+        if (cancel)
+        {
+            SendErrorStatusChange(readError, rv,
+                readError ? request : nullptr, data->mFile);
+        }
+    }
+
+    // Cancel reading?
+    if (cancel)
+    {
+        EndDownload(NS_BINDING_ABORTED);
+    }
+
+    return NS_OK;
+}
+
+
+//*****************************************************************************
+// nsWebBrowserPersist::nsIProgressEventSink
+//*****************************************************************************
+
+NS_IMETHODIMP nsWebBrowserPersist::OnProgress(
+    nsIRequest *request, nsISupports *ctxt, int64_t aProgress,
+    int64_t aProgressMax)
+{
+    if (!mProgressListener)
+    {
+        return NS_OK;
+    }
+
+    // Store the progress of this request
+    nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(request);
+    OutputData *data = mOutputMap.Get(keyPtr);
+    if (data)
+    {
+        data->mSelfProgress = aProgress;
+        data->mSelfProgressMax = aProgressMax;
+    }
+    else
+    {
+        UploadData *upData = mUploadList.Get(keyPtr);
+        if (upData)
+        {
+            upData->mSelfProgress = aProgress;
+            upData->mSelfProgressMax = aProgressMax;
+        }
+    }
+
+    // Notify listener of total progress
+    CalcTotalProgress();
+    if (mProgressListener2)
+    {
+      mProgressListener2->OnProgressChange64(nullptr, request, aProgress,
+            aProgressMax, mTotalCurrentProgress, mTotalMaxProgress);
+    }
+    else
+    {
+      // have to truncate 64-bit to 32bit
+      mProgressListener->OnProgressChange(nullptr, request, uint64_t(aProgress),
+              uint64_t(aProgressMax), mTotalCurrentProgress, mTotalMaxProgress);
+    }
+
+    // If our progress listener implements nsIProgressEventSink,
+    // forward the notification
+    if (mEventSink)
+    {
+        mEventSink->OnProgress(request, ctxt, aProgress, aProgressMax);
+    }
+
+    return NS_OK;
+}
+
+NS_IMETHODIMP nsWebBrowserPersist::OnStatus(
+    nsIRequest *request, nsISupports *ctxt, nsresult status,
+    const char16_t *statusArg)
+{
+    if (mProgressListener)
+    {
+        // We need to filter out non-error error codes.
+        // Is the only NS_SUCCEEDED value NS_OK?
+        switch ( status )
+        {
+        case NS_NET_STATUS_RESOLVING_HOST:
+        case NS_NET_STATUS_RESOLVED_HOST:
+        case NS_NET_STATUS_BEGIN_FTP_TRANSACTION:
+        case NS_NET_STATUS_END_FTP_TRANSACTION:
+        case NS_NET_STATUS_CONNECTING_TO:
+        case NS_NET_STATUS_CONNECTED_TO:
+        case NS_NET_STATUS_SENDING_TO:
+        case NS_NET_STATUS_RECEIVING_FROM:
+        case NS_NET_STATUS_WAITING_FOR:
+        case NS_NET_STATUS_READING:
+        case NS_NET_STATUS_WRITING:
+            break;
+
+        default:
+            // Pass other notifications (for legitimate errors) along.
+            mProgressListener->OnStatusChange(nullptr, request, status, statusArg);
+            break;
+        }
+
+    }
+
+    // If our progress listener implements nsIProgressEventSink,
+    // forward the notification
+    if (mEventSink)
+    {
+        mEventSink->OnStatus(request, ctxt, status, statusArg);
+    }
+
+    return NS_OK;
+}
+
+
+//*****************************************************************************
+// nsWebBrowserPersist private methods
+//*****************************************************************************
+
+// Convert error info into proper message text and send OnStatusChange notification
+// to the web progress listener.
+nsresult nsWebBrowserPersist::SendErrorStatusChange(
+    bool aIsReadError, nsresult aResult, nsIRequest *aRequest, nsIURI *aURI)
+{
+    NS_ENSURE_ARG_POINTER(aURI);
+
+    if (!mProgressListener)
+    {
+        // Do nothing
+        return NS_OK;
+    }
+
+    // Get the file path or spec from the supplied URI
+    nsCOMPtr<nsIFile> file;
+    GetLocalFileFromURI(aURI, getter_AddRefs(file));
+    nsAutoString path;
+    nsresult rv;
+    if (file)
+    {
+        file->GetPath(path);
+    }
+    else
+    {
+        nsAutoCString fileurl;
+        rv = aURI->GetSpec(fileurl);
+        NS_ENSURE_SUCCESS(rv, rv);
+        AppendUTF8toUTF16(fileurl, path);
+    }
+
+    nsAutoString msgId;
+    switch(aResult)
+    {
+    case NS_ERROR_FILE_NAME_TOO_LONG:
+        // File name too long.
+        msgId.AssignLiteral("fileNameTooLongError");
+        break;
+    case NS_ERROR_FILE_ALREADY_EXISTS:
+        // File exists with same name as directory.
+        msgId.AssignLiteral("fileAlreadyExistsError");
+        break;
+    case NS_ERROR_FILE_DISK_FULL:
+    case NS_ERROR_FILE_NO_DEVICE_SPACE:
+        // Out of space on target volume.
+        msgId.AssignLiteral("diskFull");
+        break;
+
+    case NS_ERROR_FILE_READ_ONLY:
+        // Attempt to write to read/only file.
+        msgId.AssignLiteral("readOnly");
+        break;
+
+    case NS_ERROR_FILE_ACCESS_DENIED:
+        // Attempt to write without sufficient permissions.
+        msgId.AssignLiteral("accessError");
+        break;
+
+    default:
+        // Generic read/write error message.
+        if (aIsReadError)
+            msgId.AssignLiteral("readError");
+        else
+            msgId.AssignLiteral("writeError");
+        break;
+    }
+    // Get properties file bundle and extract status string.
+    nsCOMPtr<nsIStringBundleService> s = do_GetService(NS_STRINGBUNDLE_CONTRACTID, &rv);
+    NS_ENSURE_TRUE(NS_SUCCEEDED(rv) && s, NS_ERROR_FAILURE);
+
+    nsCOMPtr<nsIStringBundle> bundle;
+    rv = s->CreateBundle(kWebBrowserPersistStringBundle, getter_AddRefs(bundle));
+    NS_ENSURE_TRUE(NS_SUCCEEDED(rv) && bundle, NS_ERROR_FAILURE);
+
+    nsXPIDLString msgText;
+    const char16_t *strings[1];
+    strings[0] = path.get();
+    rv = bundle->FormatStringFromName(msgId.get(), strings, 1, getter_Copies(msgText));
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+    mProgressListener->OnStatusChange(nullptr, aRequest, aResult, msgText);
+
+    return NS_OK;
+}
+
+nsresult nsWebBrowserPersist::GetValidURIFromObject(nsISupports *aObject, nsIURI **aURI) const
+{
+    NS_ENSURE_ARG_POINTER(aObject);
+    NS_ENSURE_ARG_POINTER(aURI);
+
+    nsCOMPtr<nsIFile> objAsFile = do_QueryInterface(aObject);
+    if (objAsFile)
+    {
+        return NS_NewFileURI(aURI, objAsFile);
+    }
+    nsCOMPtr<nsIURI> objAsURI = do_QueryInterface(aObject);
+    if (objAsURI)
+    {
+        *aURI = objAsURI;
+        NS_ADDREF(*aURI);
+        return NS_OK;
+    }
+
+    return NS_ERROR_FAILURE;
+}
+
+/* static */ nsresult
+nsWebBrowserPersist::GetLocalFileFromURI(nsIURI *aURI, nsIFile **aLocalFile)
+{
+    nsresult rv;
+
+    nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(aURI, &rv);
+    if (NS_FAILED(rv))
+        return rv;
+
+    nsCOMPtr<nsIFile> file;
+    rv = fileURL->GetFile(getter_AddRefs(file));
+    if (NS_FAILED(rv)) {
+        return rv;
+    }
+
+    file.forget(aLocalFile);
+    return NS_OK;
+}
+
+/* static */ nsresult
+nsWebBrowserPersist::AppendPathToURI(nsIURI *aURI, const nsAString & aPath)
+{
+    NS_ENSURE_ARG_POINTER(aURI);
+
+    nsAutoCString newPath;
+    nsresult rv = aURI->GetPath(newPath);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+    // Append a forward slash if necessary
+    int32_t len = newPath.Length();
+    if (len > 0 && newPath.CharAt(len - 1) != '/')
+    {
+        newPath.Append('/');
+    }
+
+    // Store the path back on the URI
+    AppendUTF16toUTF8(aPath, newPath);
+    aURI->SetPath(newPath);
+
+    return NS_OK;
+}
+
+nsresult nsWebBrowserPersist::SaveURIInternal(
+    nsIURI *aURI, nsISupports *aCacheKey, nsIURI *aReferrer,
+    uint32_t aReferrerPolicy, nsIInputStream *aPostData,
+    const char *aExtraHeaders, nsIURI *aFile,
+    bool aCalcFileExt, bool aIsPrivate)
+{
+    NS_ENSURE_ARG_POINTER(aURI);
+    NS_ENSURE_ARG_POINTER(aFile);
+
+    nsresult rv = NS_OK;
+
+    mURI = aURI;
+
+    nsLoadFlags loadFlags = nsIRequest::LOAD_NORMAL;
+    if (mPersistFlags & PERSIST_FLAGS_BYPASS_CACHE)
+    {
+        loadFlags |= nsIRequest::LOAD_BYPASS_CACHE;
+    }
+    else if (mPersistFlags & PERSIST_FLAGS_FROM_CACHE)
+    {
+        loadFlags |= nsIRequest::LOAD_FROM_CACHE;
+    }
+
+    // Extract the cache key
+    nsCOMPtr<nsISupports> cacheKey;
+    if (aCacheKey)
+    {
+        // Test if the cache key is actually a web page descriptor (docshell)
+        // or session history entry.
+        nsCOMPtr<nsISHEntry> shEntry = do_QueryInterface(aCacheKey);
+        if (!shEntry)
+        {
+            nsCOMPtr<nsIWebPageDescriptor> webPageDescriptor =
+                do_QueryInterface(aCacheKey);
+            if (webPageDescriptor)
+            {
+                nsCOMPtr<nsISupports> currentDescriptor;
+                webPageDescriptor->GetCurrentDescriptor(getter_AddRefs(currentDescriptor));
+                shEntry = do_QueryInterface(currentDescriptor);
+            }
+        }
+
+        if (shEntry)
+        {
+            shEntry->GetCacheKey(getter_AddRefs(cacheKey));
+        }
+        else
+        {
+            // Assume a plain cache key
+            cacheKey = aCacheKey;
+        }
+    }
+
+    // Open a channel to the URI
+    nsCOMPtr<nsIChannel> inputChannel;
+    rv = NS_NewChannel(getter_AddRefs(inputChannel),
+                       aURI,
+                       nsContentUtils::GetSystemPrincipal(),
+                       nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL,
+                       nsIContentPolicy::TYPE_OTHER,
+                       nullptr,  // aLoadGroup
+                       static_cast<nsIInterfaceRequestor*>(this),
+                       loadFlags);
+
+    nsCOMPtr<nsIPrivateBrowsingChannel> pbChannel = do_QueryInterface(inputChannel);
+    if (pbChannel)
+    {
+        pbChannel->SetPrivate(aIsPrivate);
+    }
+
+    if (NS_FAILED(rv) || inputChannel == nullptr)
+    {
+        EndDownload(NS_ERROR_FAILURE);
+        return NS_ERROR_FAILURE;
+    }
+
+    // Disable content conversion
+    if (mPersistFlags & PERSIST_FLAGS_NO_CONVERSION)
+    {
+        nsCOMPtr<nsIEncodedChannel> encodedChannel(do_QueryInterface(inputChannel));
+        if (encodedChannel)
+        {
+            encodedChannel->SetApplyConversion(false);
+        }
+    }
+
+    if (mPersistFlags & PERSIST_FLAGS_FORCE_ALLOW_COOKIES)
+    {
+        nsCOMPtr<nsIHttpChannelInternal> httpChannelInternal =
+                do_QueryInterface(inputChannel);
+        if (httpChannelInternal)
+            httpChannelInternal->SetThirdPartyFlags(nsIHttpChannelInternal::THIRD_PARTY_FORCE_ALLOW);
+    }
+
+    // Set the referrer, post data and headers if any
+    nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(inputChannel));
+    if (httpChannel)
+    {
+        // Referrer
+        if (aReferrer)
+        {
+            httpChannel->SetReferrerWithPolicy(aReferrer, aReferrerPolicy);
+        }
+
+        // Post data
+        if (aPostData)
+        {
+            nsCOMPtr<nsISeekableStream> stream(do_QueryInterface(aPostData));
+            if (stream)
+            {
+                // Rewind the postdata stream
+                stream->Seek(nsISeekableStream::NS_SEEK_SET, 0);
+                nsCOMPtr<nsIUploadChannel> uploadChannel(do_QueryInterface(httpChannel));
+                NS_ASSERTION(uploadChannel, "http must support nsIUploadChannel");
+                // Attach the postdata to the http channel
+                uploadChannel->SetUploadStream(aPostData, EmptyCString(), -1);
+            }
+        }
+
+        // Cache key
+        nsCOMPtr<nsICacheInfoChannel> cacheChannel(do_QueryInterface(httpChannel));
+        if (cacheChannel && cacheKey)
+        {
+            cacheChannel->SetCacheKey(cacheKey);
+        }
+
+        // Headers
+        if (aExtraHeaders)
+        {
+            nsAutoCString oneHeader;
+            nsAutoCString headerName;
+            nsAutoCString headerValue;
+            int32_t crlf = 0;
+            int32_t colon = 0;
+            const char *kWhitespace = "\b\t\r\n ";
+            nsAutoCString extraHeaders(aExtraHeaders);
+            while (true)
+            {
+                crlf = extraHeaders.Find("\r\n", true);
+                if (crlf == -1)
+                    break;
+                extraHeaders.Mid(oneHeader, 0, crlf);
+                extraHeaders.Cut(0, crlf + 2);
+                colon = oneHeader.Find(":");
+                if (colon == -1)
+                    break; // Should have a colon
+                oneHeader.Left(headerName, colon);
+                colon++;
+                oneHeader.Mid(headerValue, colon, oneHeader.Length() - colon);
+                headerName.Trim(kWhitespace);
+                headerValue.Trim(kWhitespace);
+                // Add the header (merging if required)
+                rv = httpChannel->SetRequestHeader(headerName, headerValue, true);
+                if (NS_FAILED(rv))
+                {
+                    EndDownload(NS_ERROR_FAILURE);
+                    return NS_ERROR_FAILURE;
+                }
+            }
+        }
+    }
+    return SaveChannelInternal(inputChannel, aFile, aCalcFileExt);
+}
+
+nsresult nsWebBrowserPersist::SaveChannelInternal(
+    nsIChannel *aChannel, nsIURI *aFile, bool aCalcFileExt)
+{
+    NS_ENSURE_ARG_POINTER(aChannel);
+    NS_ENSURE_ARG_POINTER(aFile);
+
+    // The default behaviour of SaveChannelInternal is to download the source
+    // into a storage stream and upload that to the target. MakeOutputStream
+    // special-cases a file target and creates a file output stream directly.
+    // We want to special-case a file source and create a file input stream,
+    // but we don't need to do this in the case of a file target.
+    nsCOMPtr<nsIFileChannel> fc(do_QueryInterface(aChannel));
+    nsCOMPtr<nsIFileURL> fu(do_QueryInterface(aFile));
+
+    if (fc && !fu) {
+        nsCOMPtr<nsIInputStream> fileInputStream, bufferedInputStream;
+        nsresult rv = NS_MaybeOpenChannelUsingOpen2(aChannel,
+                        getter_AddRefs(fileInputStream));
+        NS_ENSURE_SUCCESS(rv, rv);
+        rv = NS_NewBufferedInputStream(getter_AddRefs(bufferedInputStream),
+                                       fileInputStream, BUFFERED_OUTPUT_SIZE);
+        NS_ENSURE_SUCCESS(rv, rv);
+        nsAutoCString contentType;
+        aChannel->GetContentType(contentType);
+        return StartUpload(bufferedInputStream, aFile, contentType);
+    }
+
+    // Read from the input channel
+    nsresult rv = NS_MaybeOpenChannelUsingAsyncOpen2(aChannel, this);
+    if (rv == NS_ERROR_NO_CONTENT)
+    {
+        // Assume this is a protocol such as mailto: which does not feed out
+        // data and just ignore it.
+        return NS_SUCCESS_DONT_FIXUP;
+    }
+
+    if (NS_FAILED(rv))
+    {
+        // Opening failed, but do we care?
+        if (mPersistFlags & PERSIST_FLAGS_FAIL_ON_BROKEN_LINKS)
+        {
+            SendErrorStatusChange(true, rv, aChannel, aFile);
+            EndDownload(NS_ERROR_FAILURE);
+            return NS_ERROR_FAILURE;
+        }
+        return NS_SUCCESS_DONT_FIXUP;
+    }
+
+    // Add the output transport to the output map with the channel as the key
+    nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(aChannel);
+    mOutputMap.Put(keyPtr, new OutputData(aFile, mURI, aCalcFileExt));
+
+    return NS_OK;
+}
+
+nsresult
+nsWebBrowserPersist::GetExtensionForContentType(const char16_t *aContentType, char16_t **aExt)
+{
+    NS_ENSURE_ARG_POINTER(aContentType);
+    NS_ENSURE_ARG_POINTER(aExt);
+
+    *aExt = nullptr;
+
+    nsresult rv;
+    if (!mMIMEService)
+    {
+        mMIMEService = do_GetService(NS_MIMESERVICE_CONTRACTID, &rv);
+        NS_ENSURE_TRUE(mMIMEService, NS_ERROR_FAILURE);
+    }
+
+    nsAutoCString contentType;
+    contentType.AssignWithConversion(aContentType);
+    nsAutoCString ext;
+    rv = mMIMEService->GetPrimaryExtension(contentType, EmptyCString(), ext);
+    if (NS_SUCCEEDED(rv))
+    {
+        *aExt = UTF8ToNewUnicode(ext);
+        NS_ENSURE_TRUE(*aExt, NS_ERROR_OUT_OF_MEMORY);
+        return NS_OK;
+    }
+
+    return NS_ERROR_FAILURE;
+}
+
+nsresult
+nsWebBrowserPersist::SaveDocumentDeferred(mozilla::UniquePtr<WalkData>&& aData)
+{
+    nsresult rv =
+        SaveDocumentInternal(aData->mDocument, aData->mFile, aData->mDataPath);
+    if (NS_FAILED(rv)) {
+        SendErrorStatusChange(true, rv, nullptr, mURI);
+        EndDownload(rv);
+    }
+    return rv;
+}
+
+nsresult nsWebBrowserPersist::SaveDocumentInternal(
+    nsIWebBrowserPersistDocument *aDocument, nsIURI *aFile, nsIURI *aDataPath)
+{
+    mURI = nullptr;
+    NS_ENSURE_ARG_POINTER(aDocument);
+    NS_ENSURE_ARG_POINTER(aFile);
+
+    nsresult rv = aDocument->SetPersistFlags(mPersistFlags);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = aDocument->GetIsPrivate(&mIsPrivate);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // See if we can get the local file representation of this URI
+    nsCOMPtr<nsIFile> localFile;
+    rv = GetLocalFileFromURI(aFile, getter_AddRefs(localFile));
+
+    nsCOMPtr<nsIFile> localDataPath;
+    if (NS_SUCCEEDED(rv) && aDataPath)
+    {
+        // See if we can get the local file representation of this URI
+        rv = GetLocalFileFromURI(aDataPath, getter_AddRefs(localDataPath));
+        NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+    }
+
+    // Persist the main document
+    rv = aDocument->GetCharacterSet(mCurrentCharset);
+    NS_ENSURE_SUCCESS(rv, rv);
+    nsAutoCString uriSpec;
+    rv = aDocument->GetDocumentURI(uriSpec);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = NS_NewURI(getter_AddRefs(mURI), uriSpec, mCurrentCharset.get());
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = aDocument->GetBaseURI(uriSpec);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = NS_NewURI(getter_AddRefs(mCurrentBaseURI), uriSpec,
+                   mCurrentCharset.get());
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Does the caller want to fixup the referenced URIs and save those too?
+    if (aDataPath)
+    {
+        // Basic steps are these.
+        //
+        // 1. Iterate through the document (and subdocuments) building a list
+        //    of unique URIs.
+        // 2. For each URI create an OutputData entry and open a channel to save
+        //    it. As each URI is saved, discover the mime type and fix up the
+        //    local filename with the correct extension.
+        // 3. Store the document in a list and wait for URI persistence to finish
+        // 4. After URI persistence completes save the list of documents,
+        //    fixing it up as it goes out to file.
+
+        mCurrentDataPathIsRelative = false;
+        mCurrentDataPath = aDataPath;
+        mCurrentRelativePathToData = "";
+        mCurrentThingsToPersist = 0;
+        mTargetBaseURI = aFile;
+
+        // Determine if the specified data path is relative to the
+        // specified file, (e.g. c:\docs\htmldata is relative to
+        // c:\docs\myfile.htm, but not to d:\foo\data.
+
+        // Starting with the data dir work back through its parents
+        // checking if one of them matches the base directory.
+
+        if (localDataPath && localFile)
+        {
+            nsCOMPtr<nsIFile> baseDir;
+            localFile->GetParent(getter_AddRefs(baseDir));
+
+            nsAutoCString relativePathToData;
+            nsCOMPtr<nsIFile> dataDirParent;
+            dataDirParent = localDataPath;
+            while (dataDirParent)
+            {
+                bool sameDir = false;
+                dataDirParent->Equals(baseDir, &sameDir);
+                if (sameDir)
+                {
+                    mCurrentRelativePathToData = relativePathToData;
+                    mCurrentDataPathIsRelative = true;
+                    break;
+                }
+
+                nsAutoString dirName;
+                dataDirParent->GetLeafName(dirName);
+
+                nsAutoCString newRelativePathToData;
+                newRelativePathToData = NS_ConvertUTF16toUTF8(dirName)
+                                      + NS_LITERAL_CSTRING("/")
+                                      + relativePathToData;
+                relativePathToData = newRelativePathToData;
+
+                nsCOMPtr<nsIFile> newDataDirParent;
+                rv = dataDirParent->GetParent(getter_AddRefs(newDataDirParent));
+                dataDirParent = newDataDirParent;
+            }
+        }
+        else
+        {
+            // generate a relative path if possible
+            nsCOMPtr<nsIURL> pathToBaseURL(do_QueryInterface(aFile));
+            if (pathToBaseURL)
+            {
+                nsAutoCString relativePath;  // nsACString
+                if (NS_SUCCEEDED(pathToBaseURL->GetRelativeSpec(aDataPath, relativePath)))
+                {
+                    mCurrentDataPathIsRelative = true;
+                    mCurrentRelativePathToData = relativePath;
+                }
+            }
+        }
+
+        // Store the document in a list so when URI persistence is done and the
+        // filenames of saved URIs are known, the documents can be fixed up and
+        // saved
+
+        DocData *docData = new DocData;
+        docData->mBaseURI = mCurrentBaseURI;
+        docData->mCharset = mCurrentCharset;
+        docData->mDocument = aDocument;
+        docData->mFile = aFile;
+        mDocList.AppendElement(docData);
+
+        // Walk the DOM gathering a list of externally referenced URIs in the uri map
+        nsCOMPtr<nsIWebBrowserPersistResourceVisitor> visit =
+            new OnWalk(this, aFile, localDataPath);
+        return aDocument->ReadResources(visit);
+    }
+    else
+    {
+        DocData *docData = new DocData;
+        docData->mBaseURI = mCurrentBaseURI;
+        docData->mCharset = mCurrentCharset;
+        docData->mDocument = aDocument;
+        docData->mFile = aFile;
+        mDocList.AppendElement(docData);
+
+        // Not walking DOMs, so go directly to serialization.
+        SerializeNextFile();
+        return NS_OK;
+    }
+}
+
+NS_IMETHODIMP
+nsWebBrowserPersist::OnWalk::VisitResource(nsIWebBrowserPersistDocument* aDoc,
+                                           const nsACString& aURI)
+{
+    return mParent->StoreURI(nsAutoCString(aURI).get());
+}
+
+NS_IMETHODIMP
+nsWebBrowserPersist::OnWalk::VisitDocument(nsIWebBrowserPersistDocument* aDoc,
+                                             nsIWebBrowserPersistDocument* aSubDoc)
+{
+    URIData* data = nullptr;
+    nsAutoCString uriSpec;
+    nsresult rv = aSubDoc->GetDocumentURI(uriSpec);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = mParent->StoreURI(uriSpec.get(), false, &data);
+    NS_ENSURE_SUCCESS(rv, rv);
+    if (!data) {
+        // If the URI scheme isn't persistable, then don't persist.
+        return NS_OK;
+    }
+    data->mIsSubFrame = true;
+    return mParent->SaveSubframeContent(aSubDoc, uriSpec, data);
+}
+
+
+NS_IMETHODIMP
+nsWebBrowserPersist::OnWalk::EndVisit(nsIWebBrowserPersistDocument* aDoc,
+                                      nsresult aStatus)
+{
+    if (NS_FAILED(aStatus)) {
+        mParent->SendErrorStatusChange(true, aStatus, nullptr, mFile);
+        mParent->EndDownload(aStatus);
+        return aStatus;
+    }
+    mParent->FinishSaveDocumentInternal(mFile, mDataPath);
+    return NS_OK;
+}
+
+void
+nsWebBrowserPersist::FinishSaveDocumentInternal(nsIURI* aFile,
+                                                nsIFile* aDataPath)
+{
+    // If there are things to persist, create a directory to hold them
+    if (mCurrentThingsToPersist > 0) {
+        if (aDataPath) {
+            bool exists = false;
+            bool haveDir = false;
+
+            aDataPath->Exists(&exists);
+            if (exists) {
+                aDataPath->IsDirectory(&haveDir);
+            }
+            if (!haveDir) {
+                nsresult rv =
+                    aDataPath->Create(nsIFile::DIRECTORY_TYPE, 0755);
+                if (NS_SUCCEEDED(rv)) {
+                    haveDir = true;
+                } else {
+                    SendErrorStatusChange(false, rv, nullptr, aFile);
+                }
+            }
+            if (!haveDir) {
+                EndDownload(NS_ERROR_FAILURE);
+                return;
+            }
+            if (mPersistFlags & PERSIST_FLAGS_CLEANUP_ON_FAILURE) {
+                // Add to list of things to delete later if all goes wrong
+                CleanupData *cleanupData = new CleanupData;
+                cleanupData->mFile = aDataPath;
+                cleanupData->mIsDirectory = true;
+                mCleanupList.AppendElement(cleanupData);
+            }
+        }
+    }
+
+    if (mWalkStack.Length() > 0) {
+        mozilla::UniquePtr<WalkData> toWalk;
+        mWalkStack.LastElement().swap(toWalk);
+        mWalkStack.TruncateLength(mWalkStack.Length() - 1);
+        // Bounce this off the event loop to avoid stack overflow.
+        typedef StoreCopyPassByRRef<decltype(toWalk)> WalkStorage;
+        auto saveMethod = &nsWebBrowserPersist::SaveDocumentDeferred;
+        nsCOMPtr<nsIRunnable> saveLater =
+            NewRunnableMethod<WalkStorage>(this, saveMethod,
+                                           mozilla::Move(toWalk));
+        NS_DispatchToCurrentThread(saveLater);
+    } else {
+        // Done walking DOMs; on to the serialization phase.
+        SerializeNextFile();
+    }
+}
+
+void nsWebBrowserPersist::Cleanup()
+{
+    mURIMap.Clear();
+    for (auto iter = mOutputMap.Iter(); !iter.Done(); iter.Next()) {
+        nsCOMPtr<nsIChannel> channel = do_QueryInterface(iter.Key());
+        if (channel) {
+            channel->Cancel(NS_BINDING_ABORTED);
+        }
+    }
+    mOutputMap.Clear();
+
+    for (auto iter = mUploadList.Iter(); !iter.Done(); iter.Next()) {
+        nsCOMPtr<nsIChannel> channel = do_QueryInterface(iter.Key());
+        if (channel) {
+            channel->Cancel(NS_BINDING_ABORTED);
+        }
+    }
+    mUploadList.Clear();
+
+    uint32_t i;
+    for (i = 0; i < mDocList.Length(); i++) {
+        DocData *docData = mDocList.ElementAt(i);
+        delete docData;
+    }
+    mDocList.Clear();
+
+    for (i = 0; i < mCleanupList.Length(); i++) {
+        CleanupData *cleanupData = mCleanupList.ElementAt(i);
+        delete cleanupData;
+    }
+    mCleanupList.Clear();
+
+    mFilenameList.Clear();
+}
+
+void nsWebBrowserPersist::CleanupLocalFiles()
+{
+    // Two passes, the first pass cleans up files, the second pass tests
+    // for and then deletes empty directories. Directories that are not
+    // empty after the first pass must contain files from something else
+    // and are not deleted.
+    int pass;
+    for (pass = 0; pass < 2; pass++)
+    {
+        uint32_t i;
+        for (i = 0; i < mCleanupList.Length(); i++)
+        {
+            CleanupData *cleanupData = mCleanupList.ElementAt(i);
+            nsCOMPtr<nsIFile> file = cleanupData->mFile;
+
+            // Test if the dir / file exists (something in an earlier loop
+            // may have already removed it)
+            bool exists = false;
+            file->Exists(&exists);
+            if (!exists)
+                continue;
+
+            // Test if the file has changed in between creation and deletion
+            // in some way that means it should be ignored
+            bool isDirectory = false;
+            file->IsDirectory(&isDirectory);
+            if (isDirectory != cleanupData->mIsDirectory)
+                continue; // A file has become a dir or vice versa !
+
+            if (pass == 0 && !isDirectory)
+            {
+                file->Remove(false);
+            }
+            else if (pass == 1 && isDirectory) // Directory
+            {
+                // Directories are more complicated. Enumerate through
+                // children looking for files. Any files created by the
+                // persist object would have been deleted by the first
+                // pass so if there are any there at this stage, the dir
+                // cannot be deleted because it has someone else's files
+                // in it. Empty child dirs are deleted but they must be
+                // recursed through to ensure they are actually empty.
+
+                bool isEmptyDirectory = true;
+                nsCOMArray<nsISimpleEnumerator> dirStack;
+                int32_t stackSize = 0;
+
+                // Push the top level enum onto the stack
+                nsCOMPtr<nsISimpleEnumerator> pos;
+                if (NS_SUCCEEDED(file->GetDirectoryEntries(getter_AddRefs(pos))))
+                    dirStack.AppendObject(pos);
+
+                while (isEmptyDirectory && (stackSize = dirStack.Count()))
+                {
+                    // Pop the last element
+                    nsCOMPtr<nsISimpleEnumerator> curPos;
+                    curPos = dirStack[stackSize-1];
+                    dirStack.RemoveObjectAt(stackSize - 1);
+
+                    // Test if the enumerator has any more files in it
+                    bool hasMoreElements = false;
+                    curPos->HasMoreElements(&hasMoreElements);
+                    if (!hasMoreElements)
+                    {
+                        continue;
+                    }
+
+                    // Child files automatically make this code drop out,
+                    // while child dirs keep the loop going.
+                    nsCOMPtr<nsISupports> child;
+                    curPos->GetNext(getter_AddRefs(child));
+                    NS_ASSERTION(child, "No child element, but hasMoreElements says otherwise");
+                    if (!child)
+                        continue;
+                    nsCOMPtr<nsIFile> childAsFile = do_QueryInterface(child);
+                    NS_ASSERTION(childAsFile, "This should be a file but isn't");
+
+                    bool childIsSymlink = false;
+                    childAsFile->IsSymlink(&childIsSymlink);
+                    bool childIsDir = false;
+                    childAsFile->IsDirectory(&childIsDir);
+                    if (!childIsDir || childIsSymlink)
+                    {
+                        // Some kind of file or symlink which means dir
+                        // is not empty so just drop out.
+                        isEmptyDirectory = false;
+                        break;
+                    }
+                    // Push parent enumerator followed by child enumerator
+                    nsCOMPtr<nsISimpleEnumerator> childPos;
+                    childAsFile->GetDirectoryEntries(getter_AddRefs(childPos));
+                    dirStack.AppendObject(curPos);
+                    if (childPos)
+                        dirStack.AppendObject(childPos);
+
+                }
+                dirStack.Clear();
+
+                // If after all that walking the dir is deemed empty, delete it
+                if (isEmptyDirectory)
+                {
+                    file->Remove(true);
+                }
+            }
+        }
+    }
+}
+
+nsresult
+nsWebBrowserPersist::CalculateUniqueFilename(nsIURI *aURI)
+{
+    nsCOMPtr<nsIURL> url(do_QueryInterface(aURI));
+    NS_ENSURE_TRUE(url, NS_ERROR_FAILURE);
+
+    bool nameHasChanged = false;
+    nsresult rv;
+
+    // Get the old filename
+    nsAutoCString filename;
+    rv = url->GetFileName(filename);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+    nsAutoCString directory;
+    rv = url->GetDirectory(directory);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+    // Split the filename into a base and an extension.
+    // e.g. "foo.html" becomes "foo" & ".html"
+    //
+    // The nsIURL methods GetFileBaseName & GetFileExtension don't
+    // preserve the dot whereas this code does to save some effort
+    // later when everything is put back together.
+    int32_t lastDot = filename.RFind(".");
+    nsAutoCString base;
+    nsAutoCString ext;
+    if (lastDot >= 0)
+    {
+        filename.Mid(base, 0, lastDot);
+        filename.Mid(ext, lastDot, filename.Length() - lastDot); // includes dot
+    }
+    else
+    {
+        // filename contains no dot
+        base = filename;
+    }
+
+    // Test if the filename is longer than allowed by the OS
+    int32_t needToChop = filename.Length() - kDefaultMaxFilenameLength;
+    if (needToChop > 0)
+    {
+        // Truncate the base first and then the ext if necessary
+        if (base.Length() > (uint32_t) needToChop)
+        {
+            base.Truncate(base.Length() - needToChop);
+        }
+        else
+        {
+            needToChop -= base.Length() - 1;
+            base.Truncate(1);
+            if (ext.Length() > (uint32_t) needToChop)
+            {
+                ext.Truncate(ext.Length() - needToChop);
+            }
+            else
+            {
+                ext.Truncate(0);
+            }
+            // If kDefaultMaxFilenameLength were 1 we'd be in trouble here,
+            // but that won't happen because it will be set to a sensible
+            // value.
+        }
+
+        filename.Assign(base);
+        filename.Append(ext);
+        nameHasChanged = true;
+    }
+
+    // Ensure the filename is unique
+    // Create a filename if it's empty, or if the filename / datapath is
+    // already taken by another URI and create an alternate name.
+
+    if (base.IsEmpty() || !mFilenameList.IsEmpty())
+    {
+        nsAutoCString tmpPath;
+        nsAutoCString tmpBase;
+        uint32_t duplicateCounter = 1;
+        while (1)
+        {
+            // Make a file name,
+            // Foo become foo_001, foo_002, etc.
+            // Empty files become _001, _002 etc.
+
+            if (base.IsEmpty() || duplicateCounter > 1)
+            {
+                char * tmp = PR_smprintf("_%03d", duplicateCounter);
+                NS_ENSURE_TRUE(tmp, NS_ERROR_OUT_OF_MEMORY);
+                if (filename.Length() < kDefaultMaxFilenameLength - 4)
+                {
+                    tmpBase = base;
+                }
+                else
+                {
+                    base.Mid(tmpBase, 0, base.Length() - 4);
+                }
+                tmpBase.Append(tmp);
+                PR_smprintf_free(tmp);
+            }
+            else
+            {
+                tmpBase = base;
+            }
+
+            tmpPath.Assign(directory);
+            tmpPath.Append(tmpBase);
+            tmpPath.Append(ext);
+
+            // Test if the name is a duplicate
+            if (!mFilenameList.Contains(tmpPath))
+            {
+                if (!base.Equals(tmpBase))
+                {
+                    filename.Assign(tmpBase);
+                    filename.Append(ext);
+                    nameHasChanged = true;
+                }
+                break;
+            }
+            duplicateCounter++;
+        }
+    }
+
+    // Add name to list of those already used
+    nsAutoCString newFilepath(directory);
+    newFilepath.Append(filename);
+    mFilenameList.AppendElement(newFilepath);
+
+    // Update the uri accordingly if the filename actually changed
+    if (nameHasChanged)
+    {
+        // Final sanity test
+        if (filename.Length() > kDefaultMaxFilenameLength)
+        {
+            NS_WARNING("Filename wasn't truncated less than the max file length - how can that be?");
+            return NS_ERROR_FAILURE;
+        }
+
+        nsCOMPtr<nsIFile> localFile;
+        GetLocalFileFromURI(aURI, getter_AddRefs(localFile));
+
+        if (localFile)
+        {
+            nsAutoString filenameAsUnichar;
+            filenameAsUnichar.AssignWithConversion(filename.get());
+            localFile->SetLeafName(filenameAsUnichar);
+
+            // Resync the URI with the file after the extension has been appended
+            nsresult rv;
+            nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(aURI, &rv);
+            NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+            fileURL->SetFile(localFile);  // this should recalculate uri
+        }
+        else
+        {
+            url->SetFileName(filename);
+        }
+    }
+
+    return NS_OK;
+}
+
+
+nsresult
+nsWebBrowserPersist::MakeFilenameFromURI(nsIURI *aURI, nsString &aFilename)
+{
+    // Try to get filename from the URI.
+    nsAutoString fileName;
+
+    // Get a suggested file name from the URL but strip it of characters
+    // likely to cause the name to be illegal.
+
+    nsCOMPtr<nsIURL> url(do_QueryInterface(aURI));
+    if (url)
+    {
+        nsAutoCString nameFromURL;
+        url->GetFileName(nameFromURL);
+        if (mPersistFlags & PERSIST_FLAGS_DONT_CHANGE_FILENAMES)
+        {
+            fileName.AssignWithConversion(NS_UnescapeURL(nameFromURL).BeginReading());
+            aFilename = fileName;
+            return NS_OK;
+        }
+        if (!nameFromURL.IsEmpty())
+        {
+            // Unescape the file name (GetFileName escapes it)
+            NS_UnescapeURL(nameFromURL);
+            uint32_t nameLength = 0;
+            const char *p = nameFromURL.get();
+            for (;*p && *p != ';' && *p != '?' && *p != '#' && *p != '.'
+                 ;p++)
+            {
+                if (nsCRT::IsAsciiAlpha(*p) || nsCRT::IsAsciiDigit(*p)
+                    || *p == '.' || *p == '-' ||  *p == '_' || (*p == ' '))
+                {
+                    fileName.Append(char16_t(*p));
+                    if (++nameLength == kDefaultMaxFilenameLength)
+                    {
+                        // Note:
+                        // There is no point going any further since it will be
+                        // truncated in CalculateUniqueFilename anyway.
+                        // More importantly, certain implementations of
+                        // nsIFile (e.g. the Mac impl) might truncate
+                        // names in undesirable ways, such as truncating from
+                        // the middle, inserting ellipsis and so on.
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    // Empty filenames can confuse the local file object later
+    // when it attempts to set the leaf name in CalculateUniqueFilename
+    // for duplicates and ends up replacing the parent dir. To avoid
+    // the problem, all filenames are made at least one character long.
+    if (fileName.IsEmpty())
+    {
+        fileName.Append(char16_t('a')); // 'a' is for arbitrary
+    }
+
+    aFilename = fileName;
+    return NS_OK;
+}
+
+
+nsresult
+nsWebBrowserPersist::CalculateAndAppendFileExt(nsIURI *aURI, nsIChannel *aChannel, nsIURI *aOriginalURIWithExtension)
+{
+    nsresult rv;
+
+    if (!mMIMEService)
+    {
+        mMIMEService = do_GetService(NS_MIMESERVICE_CONTRACTID, &rv);
+        NS_ENSURE_TRUE(mMIMEService, NS_ERROR_FAILURE);
+    }
+
+    nsAutoCString contentType;
+
+    // Get the content type from the channel
+    aChannel->GetContentType(contentType);
+
+    // Get the content type from the MIME service
+    if (contentType.IsEmpty())
+    {
+        nsCOMPtr<nsIURI> uri;
+        aChannel->GetOriginalURI(getter_AddRefs(uri));
+        mMIMEService->GetTypeFromURI(uri, contentType);
+    }
+
+    // Append the extension onto the file
+    if (!contentType.IsEmpty())
+    {
+        nsCOMPtr<nsIMIMEInfo> mimeInfo;
+        mMIMEService->GetFromTypeAndExtension(
+            contentType, EmptyCString(), getter_AddRefs(mimeInfo));
+
+        nsCOMPtr<nsIFile> localFile;
+        GetLocalFileFromURI(aURI, getter_AddRefs(localFile));
+
+        if (mimeInfo)
+        {
+            nsCOMPtr<nsIURL> url(do_QueryInterface(aURI));
+            NS_ENSURE_TRUE(url, NS_ERROR_FAILURE);
+
+            nsAutoCString newFileName;
+            url->GetFileName(newFileName);
+
+            // Test if the current extension is current for the mime type
+            bool hasExtension = false;
+            int32_t ext = newFileName.RFind(".");
+            if (ext != -1)
+            {
+                mimeInfo->ExtensionExists(Substring(newFileName, ext + 1), &hasExtension);
+            }
+
+            // Append the mime file extension
+            nsAutoCString fileExt;
+            if (!hasExtension)
+            {
+                // Test if previous extension is acceptable
+                nsCOMPtr<nsIURL> oldurl(do_QueryInterface(aOriginalURIWithExtension));
+                NS_ENSURE_TRUE(oldurl, NS_ERROR_FAILURE);
+                oldurl->GetFileExtension(fileExt);
+                bool useOldExt = false;
+                if (!fileExt.IsEmpty())
+                {
+                    mimeInfo->ExtensionExists(fileExt, &useOldExt);
+                }
+
+                // can't use old extension so use primary extension
+                if (!useOldExt)
+                {
+                    mimeInfo->GetPrimaryExtension(fileExt);
+                }
+
+                if (!fileExt.IsEmpty())
+                {
+                    uint32_t newLength = newFileName.Length() + fileExt.Length() + 1;
+                    if (newLength > kDefaultMaxFilenameLength)
+                    {
+                        if (fileExt.Length() > kDefaultMaxFilenameLength/2)
+                            fileExt.Truncate(kDefaultMaxFilenameLength/2);
+
+                        uint32_t diff = kDefaultMaxFilenameLength - 1 -
+                                        fileExt.Length();
+                        if (newFileName.Length() > diff)
+                            newFileName.Truncate(diff);
+                    }
+                    newFileName.Append('.');
+                    newFileName.Append(fileExt);
+                }
+
+                if (localFile)
+                {
+                    localFile->SetLeafName(NS_ConvertUTF8toUTF16(newFileName));
+
+                    // Resync the URI with the file after the extension has been appended
+                    nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(aURI, &rv);
+                    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+                    fileURL->SetFile(localFile);  // this should recalculate uri
+                }
+                else
+                {
+                    url->SetFileName(newFileName);
+                }
+            }
+
+        }
+    }
+
+    return NS_OK;
+}
+
+nsresult
+nsWebBrowserPersist::MakeOutputStream(
+    nsIURI *aURI, nsIOutputStream **aOutputStream)
+{
+    nsresult rv;
+
+    nsCOMPtr<nsIFile> localFile;
+    GetLocalFileFromURI(aURI, getter_AddRefs(localFile));
+    if (localFile)
+        rv = MakeOutputStreamFromFile(localFile, aOutputStream);
+    else
+        rv = MakeOutputStreamFromURI(aURI, aOutputStream);
+
+    return rv;
+}
+
+nsresult
+nsWebBrowserPersist::MakeOutputStreamFromFile(
+    nsIFile *aFile, nsIOutputStream **aOutputStream)
+{
+    nsresult rv = NS_OK;
+
+    nsCOMPtr<nsIFileOutputStream> fileOutputStream =
+        do_CreateInstance(NS_LOCALFILEOUTPUTSTREAM_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+    // XXX brade:  get the right flags here!
+    int32_t ioFlags = -1;
+    if (mPersistFlags & nsIWebBrowserPersist::PERSIST_FLAGS_APPEND_TO_FILE)
+      ioFlags = PR_APPEND | PR_CREATE_FILE | PR_WRONLY;
+    rv = fileOutputStream->Init(aFile, ioFlags, -1, 0);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    *aOutputStream = NS_BufferOutputStream(fileOutputStream,
+                                           BUFFERED_OUTPUT_SIZE).take();
+
+    if (mPersistFlags & PERSIST_FLAGS_CLEANUP_ON_FAILURE)
+    {
+        // Add to cleanup list in event of failure
+        CleanupData *cleanupData = new CleanupData;
+        if (!cleanupData) {
+          NS_RELEASE(*aOutputStream);
+          return NS_ERROR_OUT_OF_MEMORY;
+        }
+        cleanupData->mFile = aFile;
+        cleanupData->mIsDirectory = false;
+        mCleanupList.AppendElement(cleanupData);
+    }
+
+    return NS_OK;
+}
+
+nsresult
+nsWebBrowserPersist::MakeOutputStreamFromURI(
+    nsIURI *aURI, nsIOutputStream  **aOutputStream)
+{
+    uint32_t segsize = 8192;
+    uint32_t maxsize = uint32_t(-1);
+    nsCOMPtr<nsIStorageStream> storStream;
+    nsresult rv = NS_NewStorageStream(segsize, maxsize, getter_AddRefs(storStream));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    NS_ENSURE_SUCCESS(CallQueryInterface(storStream, aOutputStream), NS_ERROR_FAILURE);
+    return NS_OK;
+}
+
+void
+nsWebBrowserPersist::FinishDownload()
+{
+    EndDownload(NS_OK);
+}
+
+void
+nsWebBrowserPersist::EndDownload(nsresult aResult)
+{
+    // Store the error code in the result if it is an error
+    if (NS_SUCCEEDED(mPersistResult) && NS_FAILED(aResult))
+    {
+        mPersistResult = aResult;
+    }
+
+    // mCompleted needs to be set before issuing the stop notification.
+    // (Bug 1224437)
+    mCompleted = true;
+    // State stop notification
+    if (mProgressListener) {
+        mProgressListener->OnStateChange(nullptr, nullptr,
+            nsIWebProgressListener::STATE_STOP
+            | nsIWebProgressListener::STATE_IS_NETWORK, mPersistResult);
+    }
+
+    // Do file cleanup if required
+    if (NS_FAILED(aResult) && (mPersistFlags & PERSIST_FLAGS_CLEANUP_ON_FAILURE))
+    {
+        CleanupLocalFiles();
+    }
+
+    // Cleanup the channels
+    Cleanup();
+
+    mProgressListener = nullptr;
+    mProgressListener2 = nullptr;
+    mEventSink = nullptr;
+}
+
+nsresult
+nsWebBrowserPersist::FixRedirectedChannelEntry(nsIChannel *aNewChannel)
+{
+    NS_ENSURE_ARG_POINTER(aNewChannel);
+
+    // Iterate through existing open channels looking for one with a URI
+    // matching the one specified.
+    nsCOMPtr<nsIURI> originalURI;
+    aNewChannel->GetOriginalURI(getter_AddRefs(originalURI));
+    nsISupports* matchingKey = nullptr;
+    for (auto iter = mOutputMap.Iter(); !iter.Done(); iter.Next()) {
+        nsISupports* key = iter.Key();
+        nsCOMPtr<nsIChannel> thisChannel = do_QueryInterface(key);
+        nsCOMPtr<nsIURI> thisURI;
+
+        thisChannel->GetOriginalURI(getter_AddRefs(thisURI));
+
+        // Compare this channel's URI to the one passed in.
+        bool matchingURI = false;
+        thisURI->Equals(originalURI, &matchingURI);
+        if (matchingURI) {
+            matchingKey = key;
+            break;
+        }
+    }
+
+    if (matchingKey) {
+        // If a match was found, remove the data entry with the old channel
+        // key and re-add it with the new channel key.
+        nsAutoPtr<OutputData> outputData;
+        mOutputMap.RemoveAndForget(matchingKey, outputData);
+        NS_ENSURE_TRUE(outputData, NS_ERROR_FAILURE);
+
+        // Store data again with new channel unless told to ignore redirects.
+        if (!(mPersistFlags & PERSIST_FLAGS_IGNORE_REDIRECTED_DATA)) {
+            nsCOMPtr<nsISupports> keyPtr = do_QueryInterface(aNewChannel);
+            mOutputMap.Put(keyPtr, outputData.forget());
+        }
+    }
+
+    return NS_OK;
+}
+
+void
+nsWebBrowserPersist::CalcTotalProgress()
+{
+    mTotalCurrentProgress = 0;
+    mTotalMaxProgress = 0;
+
+    if (mOutputMap.Count() > 0) {
+        // Total up the progress of each output stream
+        for (auto iter = mOutputMap.Iter(); !iter.Done(); iter.Next()) {
+            // Only count toward total progress if destination file is local.
+            OutputData* data = iter.UserData();
+            nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(data->mFile);
+            if (fileURL) {
+                mTotalCurrentProgress += data->mSelfProgress;
+                mTotalMaxProgress += data->mSelfProgressMax;
+            }
+        }
+    }
+
+    if (mUploadList.Count() > 0) {
+        // Total up the progress of each upload
+        for (auto iter = mUploadList.Iter(); !iter.Done(); iter.Next()) {
+            UploadData* data = iter.UserData();
+            if (data) {
+                mTotalCurrentProgress += data->mSelfProgress;
+                mTotalMaxProgress += data->mSelfProgressMax;
+            }
+        }
+    }
+
+    // XXX this code seems pretty bogus and pointless
+    if (mTotalCurrentProgress == 0 && mTotalMaxProgress == 0)
+    {
+        // No output streams so we must be complete
+        mTotalCurrentProgress = 10000;
+        mTotalMaxProgress = 10000;
+    }
+}
+
+nsresult
+nsWebBrowserPersist::StoreURI(
+    const char *aURI, bool aNeedsPersisting, URIData **aData)
+{
+    NS_ENSURE_ARG_POINTER(aURI);
+
+    nsCOMPtr<nsIURI> uri;
+    nsresult rv = NS_NewURI(getter_AddRefs(uri),
+                            nsDependentCString(aURI),
+                            mCurrentCharset.get(),
+                            mCurrentBaseURI);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return StoreURI(uri, aNeedsPersisting, aData);
+}
+
+nsresult
+nsWebBrowserPersist::StoreURI(
+    nsIURI *aURI, bool aNeedsPersisting, URIData **aData)
+{
+    NS_ENSURE_ARG_POINTER(aURI);
+    if (aData)
+    {
+        *aData = nullptr;
+    }
+
+    // Test if this URI should be persisted. By default
+    // we should assume the URI  is persistable.
+    bool doNotPersistURI;
+    nsresult rv = NS_URIChainHasFlags(aURI,
+                                      nsIProtocolHandler::URI_NON_PERSISTABLE,
+                                      &doNotPersistURI);
+    if (NS_FAILED(rv))
+    {
+        doNotPersistURI = false;
+    }
+
+    if (doNotPersistURI)
+    {
+        return NS_OK;
+    }
+
+    URIData *data = nullptr;
+    MakeAndStoreLocalFilenameInURIMap(aURI, aNeedsPersisting, &data);
+    if (aData)
+    {
+        *aData = data;
+    }
+
+    return NS_OK;
+}
+
+nsresult
+nsWebBrowserPersist::URIData::GetLocalURI(nsIURI *targetBaseURI, nsCString& aSpecOut)
+{
+    aSpecOut.SetIsVoid(true);
+    if (!mNeedsFixup) {
+        return NS_OK;
+    }
+    nsresult rv;
+    nsCOMPtr<nsIURI> fileAsURI;
+    if (mFile) {
+        rv = mFile->Clone(getter_AddRefs(fileAsURI));
+        NS_ENSURE_SUCCESS(rv, rv);
+    } else {
+        rv = mDataPath->Clone(getter_AddRefs(fileAsURI));
+        NS_ENSURE_SUCCESS(rv, rv);
+        rv = AppendPathToURI(fileAsURI, mFilename);
+        NS_ENSURE_SUCCESS(rv, rv);
+    }
+
+    // remove username/password if present
+    fileAsURI->SetUserPass(EmptyCString());
+
+    // reset node attribute
+    // Use relative or absolute links
+    if (mDataPathIsRelative) {
+        bool isEqual = false;
+        if (NS_SUCCEEDED(mRelativeDocumentURI->Equals(targetBaseURI, &isEqual)) && isEqual) {
+            nsCOMPtr<nsIURL> url(do_QueryInterface(fileAsURI));
+            if (!url) {
+                return NS_ERROR_FAILURE;
+            }
+            
+            nsAutoCString filename;
+            url->GetFileName(filename);
+            
+            nsAutoCString rawPathURL(mRelativePathToData);
+            rawPathURL.Append(filename);
+            
+            rv = NS_EscapeURL(rawPathURL, esc_FilePath, aSpecOut, fallible);
+            NS_ENSURE_SUCCESS(rv, rv);
+        } else {
+            nsAutoCString rawPathURL;
+            
+            nsCOMPtr<nsIFile> dataFile;
+            rv = GetLocalFileFromURI(mFile, getter_AddRefs(dataFile));
+            NS_ENSURE_SUCCESS(rv, rv);
+            
+            nsCOMPtr<nsIFile> docFile;
+            rv = GetLocalFileFromURI(targetBaseURI, getter_AddRefs(docFile));
+            NS_ENSURE_SUCCESS(rv, rv);
+            
+            nsCOMPtr<nsIFile> parentDir;
+            rv = docFile->GetParent(getter_AddRefs(parentDir));
+            NS_ENSURE_SUCCESS(rv, rv);
+            
+            rv = dataFile->GetRelativePath(parentDir, rawPathURL);
+            NS_ENSURE_SUCCESS(rv, rv);
+            
+            rv = NS_EscapeURL(rawPathURL, esc_FilePath, aSpecOut, fallible);
+            NS_ENSURE_SUCCESS(rv, rv);
+        }
+    } else {
+        fileAsURI->GetSpec(aSpecOut);
+    }
+    if (mIsSubFrame) {
+        AppendUTF16toUTF8(mSubFrameExt, aSpecOut);
+    }
+
+    return NS_OK;
+}
+
+bool
+nsWebBrowserPersist::DocumentEncoderExists(const char *aContentType)
+{
+    // Check if there is an encoder for the desired content type.
+    nsAutoCString contractID(NS_DOC_ENCODER_CONTRACTID_BASE);
+    contractID.Append(aContentType);
+
+    nsCOMPtr<nsIComponentRegistrar> registrar;
+    NS_GetComponentRegistrar(getter_AddRefs(registrar));
+    if (registrar)
+    {
+        bool result;
+        nsresult rv = registrar->IsContractIDRegistered(contractID.get(),
+                                                        &result);
+        if (NS_SUCCEEDED(rv) && result)
+        {
+            return true;
+        }
+    }
+    return false;
+}
+
+nsresult
+nsWebBrowserPersist::SaveSubframeContent(
+    nsIWebBrowserPersistDocument *aFrameContent,
+    const nsCString& aURISpec,
+    URIData *aData)
+{
+    NS_ENSURE_ARG_POINTER(aData);
+
+    // Extract the content type for the frame's contents.
+    nsAutoCString contentType;
+    nsresult rv = aFrameContent->GetContentType(contentType);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsXPIDLString ext;
+    GetExtensionForContentType(NS_ConvertASCIItoUTF16(contentType).get(),
+                               getter_Copies(ext));
+
+    // We must always have an extension so we will try to re-assign
+    // the original extension if GetExtensionForContentType fails.
+    if (ext.IsEmpty()) {
+        nsCOMPtr<nsIURI> docURI;
+        rv = NS_NewURI(getter_AddRefs(docURI), aURISpec, mCurrentCharset.get());
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        nsCOMPtr<nsIURL> url(do_QueryInterface(docURI, &rv));
+        nsAutoCString extension;
+        if (NS_SUCCEEDED(rv)) {
+            url->GetFileExtension(extension);
+        } else {
+            extension.AssignLiteral("htm");
+        }
+        aData->mSubFrameExt.Assign(char16_t('.'));
+        AppendUTF8toUTF16(extension, aData->mSubFrameExt);
+    } else {
+        aData->mSubFrameExt.Assign(char16_t('.'));
+        aData->mSubFrameExt.Append(ext);
+    }
+
+    nsString filenameWithExt = aData->mFilename;
+    filenameWithExt.Append(aData->mSubFrameExt);
+
+    // Work out the path for the subframe
+    nsCOMPtr<nsIURI> frameURI;
+    rv = mCurrentDataPath->Clone(getter_AddRefs(frameURI));
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = AppendPathToURI(frameURI, filenameWithExt);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Work out the path for the subframe data
+    nsCOMPtr<nsIURI> frameDataURI;
+    rv = mCurrentDataPath->Clone(getter_AddRefs(frameDataURI));
+    NS_ENSURE_SUCCESS(rv, rv);
+    nsAutoString newFrameDataPath(aData->mFilename);
+
+    // Append _data
+    newFrameDataPath.AppendLiteral("_data");
+    rv = AppendPathToURI(frameDataURI, newFrameDataPath);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Make frame document & data path conformant and unique
+    rv = CalculateUniqueFilename(frameURI);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = CalculateUniqueFilename(frameDataURI);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    mCurrentThingsToPersist++;
+
+    // We shouldn't use SaveDocumentInternal for the contents
+    // of frames that are not documents, e.g. images.
+    if (DocumentEncoderExists(contentType.get())) {
+        auto toWalk = mozilla::MakeUnique<WalkData>();
+        toWalk->mDocument = aFrameContent;
+        toWalk->mFile = frameURI;
+        toWalk->mDataPath = frameDataURI;
+        mWalkStack.AppendElement(mozilla::Move(toWalk));
+    } else {
+        rv = StoreURI(aURISpec.get());
+    }
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Store the updated uri to the frame
+    aData->mFile = frameURI;
+    aData->mSubFrameExt.Truncate(); // we already put this in frameURI
+
+    return NS_OK;
+}
+
+nsresult
+nsWebBrowserPersist::CreateChannelFromURI(nsIURI *aURI, nsIChannel **aChannel)
+{
+    nsresult rv = NS_OK;
+    *aChannel = nullptr;
+
+    rv = NS_NewChannel(aChannel,
+                       aURI,
+                       nsContentUtils::GetSystemPrincipal(),
+                       nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL,
+                       nsIContentPolicy::TYPE_OTHER);
+    NS_ENSURE_SUCCESS(rv, rv);
+    NS_ENSURE_ARG_POINTER(*aChannel);
+
+    rv = (*aChannel)->SetNotificationCallbacks(static_cast<nsIInterfaceRequestor*>(this));
+    NS_ENSURE_SUCCESS(rv, rv);
+    return NS_OK;
+}
+
+
+// we store the current location as the key (absolutized version of domnode's attribute's value)
+nsresult
+nsWebBrowserPersist::MakeAndStoreLocalFilenameInURIMap(
+    nsIURI *aURI, bool aNeedsPersisting, URIData **aData)
+{
+    NS_ENSURE_ARG_POINTER(aURI);
+
+    nsAutoCString spec;
+    nsresult rv = aURI->GetSpec(spec);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+    // Create a sensibly named filename for the URI and store in the URI map
+    URIData *data;
+    if (mURIMap.Contains(spec))
+    {
+        data = mURIMap.Get(spec);
+        if (aNeedsPersisting)
+        {
+          data->mNeedsPersisting = true;
+        }
+        if (aData)
+        {
+            *aData = data;
+        }
+        return NS_OK;
+    }
+
+    // Create a unique file name for the uri
+    nsString filename;
+    rv = MakeFilenameFromURI(aURI, filename);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+    // Store the file name
+    data = new URIData;
+    NS_ENSURE_TRUE(data, NS_ERROR_OUT_OF_MEMORY);
+
+    data->mNeedsPersisting = aNeedsPersisting;
+    data->mNeedsFixup = true;
+    data->mFilename = filename;
+    data->mSaved = false;
+    data->mIsSubFrame = false;
+    data->mDataPath = mCurrentDataPath;
+    data->mDataPathIsRelative = mCurrentDataPathIsRelative;
+    data->mRelativePathToData = mCurrentRelativePathToData;
+    data->mRelativeDocumentURI = mTargetBaseURI;
+    data->mCharset = mCurrentCharset;
+
+    if (aNeedsPersisting)
+        mCurrentThingsToPersist++;
+
+    mURIMap.Put(spec, data);
+    if (aData)
+    {
+        *aData = data;
+    }
+
+    return NS_OK;
+}
+
+// Decide if we need to apply conversion to the passed channel.
+void nsWebBrowserPersist::SetApplyConversionIfNeeded(nsIChannel *aChannel)
+{
+    nsresult rv = NS_OK;
+    nsCOMPtr<nsIEncodedChannel> encChannel = do_QueryInterface(aChannel, &rv);
+    if (NS_FAILED(rv))
+        return;
+
+    // Set the default conversion preference:
+    encChannel->SetApplyConversion(false);
+
+    nsCOMPtr<nsIURI> thisURI;
+    aChannel->GetURI(getter_AddRefs(thisURI));
+    nsCOMPtr<nsIURL> sourceURL(do_QueryInterface(thisURI));
+    if (!sourceURL)
+        return;
+    nsAutoCString extension;
+    sourceURL->GetFileExtension(extension);
+
+    nsCOMPtr<nsIUTF8StringEnumerator> encEnum;
+    encChannel->GetContentEncodings(getter_AddRefs(encEnum));
+    if (!encEnum)
+        return;
+    nsCOMPtr<nsIExternalHelperAppService> helperAppService =
+        do_GetService(NS_EXTERNALHELPERAPPSERVICE_CONTRACTID, &rv);
+    if (NS_FAILED(rv))
+        return;
+    bool hasMore;
+    rv = encEnum->HasMore(&hasMore);
+    if (NS_SUCCEEDED(rv) && hasMore)
+    {
+        nsAutoCString encType;
+        rv = encEnum->GetNext(encType);
+        if (NS_SUCCEEDED(rv))
+        {
+            bool applyConversion = false;
+            rv = helperAppService->ApplyDecodingForExtension(extension, encType,
+                                                             &applyConversion);
+            if (NS_SUCCEEDED(rv))
+                encChannel->SetApplyConversion(applyConversion);
+        }
+    }
+}