Add m-esr52 at 52.6.0

14 files changed, 4057 insertions, 0 deletions

diff --git a/uriloader/base/moz.build b/uriloader/base/moz.build
new file mode 100644
index 000000000..0d0f9a1c6
--- /dev/null
+++ b/uriloader/base/moz.build
@@ -0,0 +1,33 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+include('/ipc/chromium/chromium-config.mozbuild')
+
+XPIDL_SOURCES += [
+    'nsCURILoader.idl',
+    'nsIContentHandler.idl',
+    'nsIDocumentLoader.idl',
+    'nsITransfer.idl',
+    'nsIURIContentListener.idl',
+    'nsIURILoader.idl',
+    'nsIWebProgress.idl',
+    'nsIWebProgressListener.idl',
+    'nsIWebProgressListener2.idl',
+]
+
+XPIDL_MODULE = 'uriloader'
+
+EXPORTS += [
+    'nsDocLoader.h',
+    'nsURILoader.h',
+]
+
+UNIFIED_SOURCES += [
+    'nsDocLoader.cpp',
+    'nsURILoader.cpp',
+]
+
+FINAL_LIBRARY = 'xul'
diff --git a/uriloader/base/nsCURILoader.idl b/uriloader/base/nsCURILoader.idl
new file mode 100644
index 000000000..5d9d8f013
--- /dev/null
+++ b/uriloader/base/nsCURILoader.idl
@@ -0,0 +1,49 @@
+/* -*- Mode: IDL; tab-width: 3; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * 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 "nsIURILoader.idl"
+
+/*
+nsCURILoader implements:
+-------------------------
+nsIURILoader
+*/
+
+%{ C++
+//	{9F6D5D40-90E7-11d3-AF93-00A024FFC08C} - 
+#define NS_URI_LOADER_CID \
+{ 0x9f6d5d40, 0x90e7, 0x11d3, { 0xaf, 0x80, 0x00, 0xa0, 0x24, 0xff, 0xc0, 0x8c } }
+#define NS_URI_LOADER_CONTRACTID \
+"@mozilla.org/uriloader;1"
+
+/* 057b04d0-0ccf-11d2-beba-00805f8a66dc */
+#define NS_DOCUMENTLOADER_SERVICE_CID   \
+ { 0x057b04d0, 0x0ccf, 0x11d2,{0xbe, 0xba, 0x00, 0x80, 0x5f, 0x8a, 0x66, 0xdc}}
+
+#define NS_DOCUMENTLOADER_SERVICE_CONTRACTID \
+"@mozilla.org/docloaderservice;1"
+
+#define NS_CONTENT_HANDLER_CONTRACTID               "@mozilla.org/uriloader/content-handler;1"
+#define NS_CONTENT_HANDLER_CONTRACTID_PREFIX	     NS_CONTENT_HANDLER_CONTRACTID "?type="
+
+/**
+ * A category where content listeners can register. The name of the entry must
+ * be the content that this listener wants to handle, the value must be a
+ * contract ID for the listener. It will be created using createInstance (not
+ * getService).
+ *
+ * Listeners added this way are tried after the initial target of the load and
+ * after explicitly registered listeners (nsIURILoader::registerContentListener).
+ *
+ * These listeners must implement at least nsIURIContentListener (and
+ * nsISupports).
+ *
+ * @see nsICategoryManager
+ * @see nsIURIContentListener
+ */
+#define NS_CONTENT_LISTENER_CATEGORYMANAGER_ENTRY   "external-uricontentlisteners"
+
+%}
diff --git a/uriloader/base/nsDocLoader.cpp b/uriloader/base/nsDocLoader.cpp
new file mode 100644
index 000000000..69885b93f
--- /dev/null
+++ b/uriloader/base/nsDocLoader.cpp
@@ -0,0 +1,1516 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "nspr.h"
+#include "mozilla/Logging.h"
+
+#include "nsDocLoader.h"
+#include "nsCURILoader.h"
+#include "nsNetUtil.h"
+#include "nsIHttpChannel.h"
+#include "nsIWebProgressListener2.h"
+
+#include "nsIServiceManager.h"
+#include "nsXPIDLString.h"
+
+#include "nsIURL.h"
+#include "nsCOMPtr.h"
+#include "nscore.h"
+#include "nsWeakPtr.h"
+#include "nsAutoPtr.h"
+#include "nsQueryObject.h"
+
+#include "nsIDOMWindow.h"
+
+#include "nsIStringBundle.h"
+#include "nsIScriptSecurityManager.h"
+
+#include "nsITransport.h"
+#include "nsISocketTransport.h"
+#include "nsIDocShell.h"
+#include "nsIDOMDocument.h"
+#include "nsIDocument.h"
+#include "nsPresContext.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+
+using mozilla::DebugOnly;
+using mozilla::LogLevel;
+
+static NS_DEFINE_CID(kThisImplCID, NS_THIS_DOCLOADER_IMPL_CID);
+
+//
+// Log module for nsIDocumentLoader logging...
+//
+// To enable logging (see mozilla/Logging.h for full details):
+//
+//    set MOZ_LOG=DocLoader:5
+//    set MOZ_LOG_FILE=debug.log
+//
+// this enables LogLevel::Debug level information and places all output in
+// the file 'debug.log'.
+//
+mozilla::LazyLogModule gDocLoaderLog("DocLoader");
+
+
+#if defined(DEBUG)
+void GetURIStringFromRequest(nsIRequest* request, nsACString &name)
+{
+    if (request)
+        request->GetName(name);
+    else
+        name.AssignLiteral("???");
+}
+#endif /* DEBUG */
+
+
+
+void
+nsDocLoader::RequestInfoHashInitEntry(PLDHashEntryHdr* entry,
+                                      const void* key)
+{
+  // Initialize the entry with placement new
+  new (entry) nsRequestInfo(key);
+}
+
+void
+nsDocLoader::RequestInfoHashClearEntry(PLDHashTable* table,
+                                       PLDHashEntryHdr* entry)
+{
+  nsRequestInfo* info = static_cast<nsRequestInfo *>(entry);
+  info->~nsRequestInfo();
+}
+
+// this is used for mListenerInfoList.Contains()
+template <>
+class nsDefaultComparator <nsDocLoader::nsListenerInfo, nsIWebProgressListener*> {
+  public:
+    bool Equals(const nsDocLoader::nsListenerInfo& aInfo,
+                nsIWebProgressListener* const& aListener) const {
+      nsCOMPtr<nsIWebProgressListener> listener =
+                                       do_QueryReferent(aInfo.mWeakListener);
+      return aListener == listener;
+    }
+};
+
+/* static */ const PLDHashTableOps nsDocLoader::sRequestInfoHashOps =
+{
+  PLDHashTable::HashVoidPtrKeyStub,
+  PLDHashTable::MatchEntryStub,
+  PLDHashTable::MoveEntryStub,
+  nsDocLoader::RequestInfoHashClearEntry,
+  nsDocLoader::RequestInfoHashInitEntry
+};
+
+nsDocLoader::nsDocLoader()
+  : mParent(nullptr),
+    mCurrentSelfProgress(0),
+    mMaxSelfProgress(0),
+    mCurrentTotalProgress(0),
+    mMaxTotalProgress(0),
+    mRequestInfoHash(&sRequestInfoHashOps, sizeof(nsRequestInfo)),
+    mCompletedTotalProgress(0),
+    mIsLoadingDocument(false),
+    mIsRestoringDocument(false),
+    mDontFlushLayout(false),
+    mIsFlushingLayout(false)
+{
+  ClearInternalProgress();
+
+  MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+         ("DocLoader:%p: created.\n", this));
+}
+
+nsresult
+nsDocLoader::SetDocLoaderParent(nsDocLoader *aParent)
+{
+  mParent = aParent;
+  return NS_OK;
+}
+
+nsresult
+nsDocLoader::Init()
+{
+  nsresult rv = NS_NewLoadGroup(getter_AddRefs(mLoadGroup), this);
+  if (NS_FAILED(rv)) return rv;
+
+  MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+         ("DocLoader:%p: load group %x.\n", this, mLoadGroup.get()));
+
+  return NS_OK;
+}
+
+nsDocLoader::~nsDocLoader()
+{
+		/*
+			|ClearWeakReferences()| here is intended to prevent people holding weak references
+			from re-entering this destructor since |QueryReferent()| will |AddRef()| me, and the
+			subsequent |Release()| will try to destroy me.  At this point there should be only
+			weak references remaining (otherwise, we wouldn't be getting destroyed).
+
+			An alternative would be incrementing our refcount (consider it a compressed flag
+			saying "Don't re-destroy.").  I haven't yet decided which is better. [scc]
+		*/
+  // XXXbz now that NS_IMPL_RELEASE stabilizes by setting refcount to 1, is
+  // this needed?
+  ClearWeakReferences();
+
+  Destroy();
+
+  MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+         ("DocLoader:%p: deleted.\n", this));
+}
+
+
+/*
+ * Implementation of ISupports methods...
+ */
+NS_IMPL_ADDREF(nsDocLoader)
+NS_IMPL_RELEASE(nsDocLoader)
+
+NS_INTERFACE_MAP_BEGIN(nsDocLoader)
+   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIRequestObserver)
+   NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
+   NS_INTERFACE_MAP_ENTRY(nsIDocumentLoader)
+   NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
+   NS_INTERFACE_MAP_ENTRY(nsIWebProgress)
+   NS_INTERFACE_MAP_ENTRY(nsIProgressEventSink)
+   NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)
+   NS_INTERFACE_MAP_ENTRY(nsIChannelEventSink)
+   NS_INTERFACE_MAP_ENTRY(nsISecurityEventSink)
+   NS_INTERFACE_MAP_ENTRY(nsISupportsPriority)
+   if (aIID.Equals(kThisImplCID))
+     foundInterface = static_cast<nsIDocumentLoader *>(this);
+   else
+NS_INTERFACE_MAP_END
+
+
+/*
+ * Implementation of nsIInterfaceRequestor methods...
+ */
+NS_IMETHODIMP nsDocLoader::GetInterface(const nsIID& aIID, void** aSink)
+{
+  nsresult rv = NS_ERROR_NO_INTERFACE;
+
+  NS_ENSURE_ARG_POINTER(aSink);
+
+  if(aIID.Equals(NS_GET_IID(nsILoadGroup))) {
+    *aSink = mLoadGroup;
+    NS_IF_ADDREF((nsISupports*)*aSink);
+    rv = NS_OK;
+  } else {
+    rv = QueryInterface(aIID, aSink);
+  }
+
+  return rv;
+}
+
+/* static */
+already_AddRefed<nsDocLoader>
+nsDocLoader::GetAsDocLoader(nsISupports* aSupports)
+{
+  RefPtr<nsDocLoader> ret = do_QueryObject(aSupports);
+  return ret.forget();
+}
+
+/* static */
+nsresult
+nsDocLoader::AddDocLoaderAsChildOfRoot(nsDocLoader* aDocLoader)
+{
+  nsresult rv;
+  nsCOMPtr<nsIDocumentLoader> docLoaderService =
+    do_GetService(NS_DOCUMENTLOADER_SERVICE_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<nsDocLoader> rootDocLoader = GetAsDocLoader(docLoaderService);
+  NS_ENSURE_TRUE(rootDocLoader, NS_ERROR_UNEXPECTED);
+
+  return rootDocLoader->AddChildLoader(aDocLoader);
+}
+
+NS_IMETHODIMP
+nsDocLoader::Stop(void)
+{
+  nsresult rv = NS_OK;
+
+  MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+         ("DocLoader:%p: Stop() called\n", this));
+
+  NS_OBSERVER_ARRAY_NOTIFY_XPCOM_OBSERVERS(mChildList, nsDocLoader, Stop, ());
+
+  if (mLoadGroup)
+    rv = mLoadGroup->Cancel(NS_BINDING_ABORTED);
+
+  // Don't report that we're flushing layout so IsBusy returns false after a
+  // Stop call.
+  mIsFlushingLayout = false;
+
+  // Clear out mChildrenInOnload.  We want to make sure to fire our
+  // onload at this point, and there's no issue with mChildrenInOnload
+  // after this, since mDocumentRequest will be null after the
+  // DocLoaderIsEmpty() call.
+  mChildrenInOnload.Clear();
+
+  // Make sure to call DocLoaderIsEmpty now so that we reset mDocumentRequest,
+  // etc, as needed.  We could be getting into here from a subframe onload, in
+  // which case the call to DocLoaderIsEmpty() is coming but hasn't quite
+  // happened yet, Canceling the loadgroup did nothing (because it was already
+  // empty), and we're about to start a new load (which is what triggered this
+  // Stop() call).
+
+  // XXXbz If the child frame loadgroups were requests in mLoadgroup, I suspect
+  // we wouldn't need the call here....
+
+  NS_ASSERTION(!IsBusy(), "Shouldn't be busy here");
+  DocLoaderIsEmpty(false);
+
+  return rv;
+}
+
+
+bool
+nsDocLoader::IsBusy()
+{
+  nsresult rv;
+
+  //
+  // A document loader is busy if either:
+  //
+  //   1. One of its children is in the middle of an onload handler.  Note that
+  //      the handler may have already removed this child from mChildList!
+  //   2. It is currently loading a document and either has parts of it still
+  //      loading, or has a busy child docloader.
+  //   3. It's currently flushing layout in DocLoaderIsEmpty().
+  //
+
+  if (mChildrenInOnload.Count() || mIsFlushingLayout) {
+    return true;
+  }
+
+  /* Is this document loader busy? */
+  if (!mIsLoadingDocument) {
+    return false;
+  }
+
+  bool busy;
+  rv = mLoadGroup->IsPending(&busy);
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+  if (busy) {
+    return true;
+  }
+
+  /* check its child document loaders... */
+  uint32_t count = mChildList.Length();
+  for (uint32_t i=0; i < count; i++) {
+    nsIDocumentLoader* loader = ChildAt(i);
+
+    // This is a safe cast, because we only put nsDocLoader objects into the
+    // array
+    if (loader && static_cast<nsDocLoader*>(loader)->IsBusy())
+      return true;
+  }
+
+  return false;
+}
+
+NS_IMETHODIMP
+nsDocLoader::GetContainer(nsISupports** aResult)
+{
+   NS_ADDREF(*aResult = static_cast<nsIDocumentLoader*>(this));
+
+   return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocLoader::GetLoadGroup(nsILoadGroup** aResult)
+{
+  nsresult rv = NS_OK;
+
+  if (nullptr == aResult) {
+    rv = NS_ERROR_NULL_POINTER;
+  } else {
+    *aResult = mLoadGroup;
+    NS_IF_ADDREF(*aResult);
+  }
+  return rv;
+}
+
+void
+nsDocLoader::Destroy()
+{
+  Stop();
+
+  // Remove the document loader from the parent list of loaders...
+  if (mParent)
+  {
+    DebugOnly<nsresult> rv = mParent->RemoveChildLoader(this);
+    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "RemoveChildLoader failed");
+  }
+
+  // Release all the information about network requests...
+  ClearRequestInfoHash();
+
+  mListenerInfoList.Clear();
+  mListenerInfoList.Compact();
+
+  mDocumentRequest = nullptr;
+
+  if (mLoadGroup)
+    mLoadGroup->SetGroupObserver(nullptr);
+
+  DestroyChildren();
+}
+
+void
+nsDocLoader::DestroyChildren()
+{
+  uint32_t count = mChildList.Length();
+  // if the doc loader still has children...we need to enumerate the
+  // children and make them null out their back ptr to the parent doc
+  // loader
+  for (uint32_t i=0; i < count; i++)
+  {
+    nsIDocumentLoader* loader = ChildAt(i);
+
+    if (loader) {
+      // This is a safe cast, as we only put nsDocLoader objects into the
+      // array
+      DebugOnly<nsresult> rv =
+        static_cast<nsDocLoader*>(loader)->SetDocLoaderParent(nullptr);
+      NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "SetDocLoaderParent failed");
+    }
+  }
+  mChildList.Clear();
+}
+
+NS_IMETHODIMP
+nsDocLoader::OnStartRequest(nsIRequest *request, nsISupports *aCtxt)
+{
+  // called each time a request is added to the group.
+
+  if (MOZ_LOG_TEST(gDocLoaderLog, LogLevel::Debug)) {
+    nsAutoCString name;
+    request->GetName(name);
+
+    uint32_t count = 0;
+    if (mLoadGroup)
+      mLoadGroup->GetActiveCount(&count);
+
+    MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+           ("DocLoader:%p: OnStartRequest[%p](%s) mIsLoadingDocument=%s, %u active URLs",
+            this, request, name.get(),
+            (mIsLoadingDocument ? "true" : "false"),
+            count));
+  }
+
+  bool bJustStartedLoading = false;
+
+  nsLoadFlags loadFlags = 0;
+  request->GetLoadFlags(&loadFlags);
+
+  if (!mIsLoadingDocument && (loadFlags & nsIChannel::LOAD_DOCUMENT_URI)) {
+      bJustStartedLoading = true;
+      mIsLoadingDocument = true;
+      ClearInternalProgress(); // only clear our progress if we are starting a new load....
+  }
+
+  //
+  // Create a new nsRequestInfo for the request that is starting to
+  // load...
+  //
+  AddRequestInfo(request);
+
+  //
+  // Only fire a doStartDocumentLoad(...) if the document loader
+  // has initiated a load...  Otherwise, this notification has
+  // resulted from a request being added to the load group.
+  //
+  if (mIsLoadingDocument) {
+    if (loadFlags & nsIChannel::LOAD_DOCUMENT_URI) {
+      //
+      // Make sure that the document channel is null at this point...
+      // (unless its been redirected)
+      //
+      NS_ASSERTION((loadFlags & nsIChannel::LOAD_REPLACE) ||
+                   !(mDocumentRequest.get()),
+                   "Overwriting an existing document channel!");
+
+      // This request is associated with the entire document...
+      mDocumentRequest = request;
+      mLoadGroup->SetDefaultLoadRequest(request);
+
+      // Only fire the start document load notification for the first
+      // document URI...  Do not fire it again for redirections
+      //
+      if (bJustStartedLoading) {
+        // Update the progress status state
+        mProgressStateFlags = nsIWebProgressListener::STATE_START;
+
+        // Fire the start document load notification
+        doStartDocumentLoad();
+        return NS_OK;
+      }
+    }
+  }
+
+  NS_ASSERTION(!mIsLoadingDocument || mDocumentRequest,
+               "mDocumentRequest MUST be set for the duration of a page load!");
+
+  doStartURLLoad(request);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocLoader::OnStopRequest(nsIRequest *aRequest,
+                           nsISupports *aCtxt,
+                           nsresult aStatus)
+{
+  nsresult rv = NS_OK;
+
+  if (MOZ_LOG_TEST(gDocLoaderLog, LogLevel::Debug)) {
+    nsAutoCString name;
+    aRequest->GetName(name);
+
+    uint32_t count = 0;
+    if (mLoadGroup)
+      mLoadGroup->GetActiveCount(&count);
+
+    MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+           ("DocLoader:%p: OnStopRequest[%p](%s) status=%x mIsLoadingDocument=%s, %u active URLs",
+           this, aRequest, name.get(),
+           aStatus, (mIsLoadingDocument ? "true" : "false"),
+           count));
+  }
+
+  bool bFireTransferring = false;
+
+  //
+  // Set the Maximum progress to the same value as the current progress.
+  // Since the URI has finished loading, all the data is there.  Also,
+  // this will allow a more accurate estimation of the max progress (in case
+  // the old value was unknown ie. -1)
+  //
+  nsRequestInfo *info = GetRequestInfo(aRequest);
+  if (info) {
+    // Null out mLastStatus now so we don't find it when looking for
+    // status from now on.  This destroys the nsStatusInfo and hence
+    // removes it from our list.
+    info->mLastStatus = nullptr;
+
+    int64_t oldMax = info->mMaxProgress;
+
+    info->mMaxProgress = info->mCurrentProgress;
+
+    //
+    // If a request whose content-length was previously unknown has just
+    // finished loading, then use this new data to try to calculate a
+    // mMaxSelfProgress...
+    //
+    if ((oldMax < int64_t(0)) && (mMaxSelfProgress < int64_t(0))) {
+      mMaxSelfProgress = CalculateMaxProgress();
+    }
+
+    // As we know the total progress of this request now, save it to be part
+    // of CalculateMaxProgress() result. We need to remove the info from the
+    // hash, see bug 480713.
+    mCompletedTotalProgress += info->mMaxProgress;
+
+    //
+    // Determine whether a STATE_TRANSFERRING notification should be
+    // 'synthesized'.
+    //
+    // If nsRequestInfo::mMaxProgress (as stored in oldMax) and
+    // nsRequestInfo::mCurrentProgress are both 0, then the
+    // STATE_TRANSFERRING notification has not been fired yet...
+    //
+    if ((oldMax == 0) && (info->mCurrentProgress == 0)) {
+      nsCOMPtr<nsIChannel> channel(do_QueryInterface(aRequest));
+
+      // Only fire a TRANSFERRING notification if the request is also a
+      // channel -- data transfer requires a nsIChannel!
+      //
+      if (channel) {
+        if (NS_SUCCEEDED(aStatus)) {
+          bFireTransferring = true;
+        }
+        //
+        // If the request failed (for any reason other than being
+        // redirected or retargeted), the TRANSFERRING notification can
+        // still be fired if a HTTP connection was established to a server.
+        //
+        else if (aStatus != NS_BINDING_REDIRECTED &&
+                 aStatus != NS_BINDING_RETARGETED) {
+          //
+          // Only if the load has been targeted (see bug 268483)...
+          //
+          uint32_t lf;
+          channel->GetLoadFlags(&lf);
+          if (lf & nsIChannel::LOAD_TARGETED) {
+            nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(aRequest));
+            if (httpChannel) {
+              uint32_t responseCode;
+              rv = httpChannel->GetResponseStatus(&responseCode);
+              if (NS_SUCCEEDED(rv)) {
+                //
+                // A valid server status indicates that a connection was
+                // established to the server... So, fire the notification
+                // even though a failure occurred later...
+                //
+                bFireTransferring = true;
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+
+  if (bFireTransferring) {
+    // Send a STATE_TRANSFERRING notification for the request.
+    int32_t flags;
+
+    flags = nsIWebProgressListener::STATE_TRANSFERRING |
+            nsIWebProgressListener::STATE_IS_REQUEST;
+    //
+    // Move the WebProgress into the STATE_TRANSFERRING state if necessary...
+    //
+    if (mProgressStateFlags & nsIWebProgressListener::STATE_START) {
+      mProgressStateFlags = nsIWebProgressListener::STATE_TRANSFERRING;
+
+      // Send STATE_TRANSFERRING for the document too...
+      flags |= nsIWebProgressListener::STATE_IS_DOCUMENT;
+    }
+
+    FireOnStateChange(this, aRequest, flags, NS_OK);
+  }
+
+  //
+  // Fire the OnStateChange(...) notification for stop request
+  //
+  doStopURLLoad(aRequest, aStatus);
+
+  // Clear this request out of the hash to avoid bypass of FireOnStateChange
+  // when address of the request is reused.
+  RemoveRequestInfo(aRequest);
+
+  //
+  // Only fire the DocLoaderIsEmpty(...) if the document loader has initiated a
+  // load.  This will handle removing the request from our hashtable as needed.
+  //
+  if (mIsLoadingDocument) {
+    nsCOMPtr<nsIDocShell> ds = do_QueryInterface(static_cast<nsIRequestObserver*>(this));
+    bool doNotFlushLayout = false;
+    if (ds) {
+      // Don't do unexpected layout flushes while we're in process of restoring
+      // a document from the bfcache.
+      ds->GetRestoringDocument(&doNotFlushLayout);
+    }
+    DocLoaderIsEmpty(!doNotFlushLayout);
+  }
+
+  return NS_OK;
+}
+
+
+nsresult nsDocLoader::RemoveChildLoader(nsDocLoader* aChild)
+{
+  nsresult rv = mChildList.RemoveElement(aChild) ? NS_OK : NS_ERROR_FAILURE;
+  if (NS_SUCCEEDED(rv)) {
+    rv = aChild->SetDocLoaderParent(nullptr);
+  }
+  return rv;
+}
+
+nsresult nsDocLoader::AddChildLoader(nsDocLoader* aChild)
+{
+  nsresult rv = mChildList.AppendElement(aChild) ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
+  if (NS_SUCCEEDED(rv)) {
+    rv = aChild->SetDocLoaderParent(this);
+  }
+  return rv;
+}
+
+NS_IMETHODIMP nsDocLoader::GetDocumentChannel(nsIChannel ** aChannel)
+{
+  if (!mDocumentRequest) {
+    *aChannel = nullptr;
+    return NS_OK;
+  }
+
+  return CallQueryInterface(mDocumentRequest, aChannel);
+}
+
+
+void nsDocLoader::DocLoaderIsEmpty(bool aFlushLayout)
+{
+  if (mIsLoadingDocument) {
+    /* In the unimagineably rude circumstance that onload event handlers
+       triggered by this function actually kill the window ... ok, it's
+       not unimagineable; it's happened ... this deathgrip keeps this object
+       alive long enough to survive this function call. */
+    nsCOMPtr<nsIDocumentLoader> kungFuDeathGrip(this);
+
+    // Don't flush layout if we're still busy.
+    if (IsBusy()) {
+      return;
+    }
+
+    NS_ASSERTION(!mIsFlushingLayout, "Someone screwed up");
+    NS_ASSERTION(mDocumentRequest, "No Document Request!");
+
+    // The load group for this DocumentLoader is idle.  Flush if we need to.
+    if (aFlushLayout && !mDontFlushLayout) {
+      nsCOMPtr<nsIDOMDocument> domDoc = do_GetInterface(GetAsSupports(this));
+      nsCOMPtr<nsIDocument> doc = do_QueryInterface(domDoc);
+      if (doc) {
+        // We start loads from style resolution, so we need to flush out style
+        // no matter what.  If we have user fonts, we also need to flush layout,
+        // since the reflow is what starts font loads.
+        mozFlushType flushType = Flush_Style;
+        nsIPresShell* shell = doc->GetShell();
+        if (shell) {
+          // Be safe in case this presshell is in teardown now
+          nsPresContext* presContext = shell->GetPresContext();
+          if (presContext && presContext->GetUserFontSet()) {
+            flushType = Flush_Layout;
+          }
+        }
+        mDontFlushLayout = mIsFlushingLayout = true;
+        doc->FlushPendingNotifications(flushType);
+        mDontFlushLayout = mIsFlushingLayout = false;
+      }
+    }
+
+    // And now check whether we're really busy; that might have changed with
+    // the layout flush.
+    // Note, mDocumentRequest can be null if the flushing above re-entered this
+    // method.
+    if (!IsBusy() && mDocumentRequest) {
+      // Clear out our request info hash, now that our load really is done and
+      // we don't need it anymore to CalculateMaxProgress().
+      ClearInternalProgress();
+
+      MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+             ("DocLoader:%p: Is now idle...\n", this));
+
+      nsCOMPtr<nsIRequest> docRequest = mDocumentRequest;
+
+      mDocumentRequest = nullptr;
+      mIsLoadingDocument = false;
+
+      // Update the progress status state - the document is done
+      mProgressStateFlags = nsIWebProgressListener::STATE_STOP;
+
+
+      nsresult loadGroupStatus = NS_OK;
+      mLoadGroup->GetStatus(&loadGroupStatus);
+
+      //
+      // New code to break the circular reference between
+      // the load group and the docloader...
+      //
+      mLoadGroup->SetDefaultLoadRequest(nullptr);
+
+      // Take a ref to our parent now so that we can call DocLoaderIsEmpty() on
+      // it even if our onload handler removes us from the docloader tree.
+      RefPtr<nsDocLoader> parent = mParent;
+
+      // Note that if calling ChildEnteringOnload() on the parent returns false
+      // then calling our onload handler is not safe.  That can only happen on
+      // OOM, so that's ok.
+      if (!parent || parent->ChildEnteringOnload(this)) {
+        // Do nothing with our state after firing the
+        // OnEndDocumentLoad(...). The document loader may be loading a *new*
+        // document - if LoadDocument() was called from a handler!
+        //
+        doStopDocumentLoad(docRequest, loadGroupStatus);
+
+        if (parent) {
+          parent->ChildDoneWithOnload(this);
+        }
+      }
+    }
+  }
+}
+
+void nsDocLoader::doStartDocumentLoad(void)
+{
+
+#if defined(DEBUG)
+  nsAutoCString buffer;
+
+  GetURIStringFromRequest(mDocumentRequest, buffer);
+  MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+         ("DocLoader:%p: ++ Firing OnStateChange for start document load (...)."
+          "\tURI: %s \n",
+          this, buffer.get()));
+#endif /* DEBUG */
+
+  // Fire an OnStatus(...) notification STATE_START.  This indicates
+  // that the document represented by mDocumentRequest has started to
+  // load...
+  FireOnStateChange(this,
+                    mDocumentRequest,
+                    nsIWebProgressListener::STATE_START |
+                    nsIWebProgressListener::STATE_IS_DOCUMENT |
+                    nsIWebProgressListener::STATE_IS_REQUEST |
+                    nsIWebProgressListener::STATE_IS_WINDOW |
+                    nsIWebProgressListener::STATE_IS_NETWORK,
+                    NS_OK);
+}
+
+void nsDocLoader::doStartURLLoad(nsIRequest *request)
+{
+#if defined(DEBUG)
+  nsAutoCString buffer;
+
+  GetURIStringFromRequest(request, buffer);
+    MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+          ("DocLoader:%p: ++ Firing OnStateChange start url load (...)."
+           "\tURI: %s\n",
+            this, buffer.get()));
+#endif /* DEBUG */
+
+  FireOnStateChange(this,
+                    request,
+                    nsIWebProgressListener::STATE_START |
+                    nsIWebProgressListener::STATE_IS_REQUEST,
+                    NS_OK);
+}
+
+void nsDocLoader::doStopURLLoad(nsIRequest *request, nsresult aStatus)
+{
+#if defined(DEBUG)
+  nsAutoCString buffer;
+
+  GetURIStringFromRequest(request, buffer);
+    MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+          ("DocLoader:%p: ++ Firing OnStateChange for end url load (...)."
+           "\tURI: %s status=%x\n",
+            this, buffer.get(), aStatus));
+#endif /* DEBUG */
+
+  FireOnStateChange(this,
+                    request,
+                    nsIWebProgressListener::STATE_STOP |
+                    nsIWebProgressListener::STATE_IS_REQUEST,
+                    aStatus);
+
+  // Fire a status change message for the most recent unfinished
+  // request to make sure that the displayed status is not outdated.
+  if (!mStatusInfoList.isEmpty()) {
+    nsStatusInfo* statusInfo = mStatusInfoList.getFirst();
+    FireOnStatusChange(this, statusInfo->mRequest,
+                       statusInfo->mStatusCode,
+                       statusInfo->mStatusMessage.get());
+  }
+}
+
+void nsDocLoader::doStopDocumentLoad(nsIRequest *request,
+                                         nsresult aStatus)
+{
+#if defined(DEBUG)
+  nsAutoCString buffer;
+
+  GetURIStringFromRequest(request, buffer);
+  MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+         ("DocLoader:%p: ++ Firing OnStateChange for end document load (...)."
+         "\tURI: %s Status=%x\n",
+          this, buffer.get(), aStatus));
+#endif /* DEBUG */
+
+  // Firing STATE_STOP|STATE_IS_DOCUMENT will fire onload handlers.
+  // Grab our parent chain before doing that so we can still dispatch
+  // STATE_STOP|STATE_IS_WINDW_STATE_IS_NETWORK to them all, even if
+  // the onload handlers rearrange the docshell tree.
+  WebProgressList list;
+  GatherAncestorWebProgresses(list);
+
+  //
+  // Fire an OnStateChange(...) notification indicating the the
+  // current document has finished loading...
+  //
+  int32_t flags = nsIWebProgressListener::STATE_STOP |
+                  nsIWebProgressListener::STATE_IS_DOCUMENT;
+  for (uint32_t i = 0; i < list.Length(); ++i) {
+    list[i]->DoFireOnStateChange(this, request, flags, aStatus);
+  }
+
+  //
+  // Fire a final OnStateChange(...) notification indicating the the
+  // current document has finished loading...
+  //
+  flags = nsIWebProgressListener::STATE_STOP |
+          nsIWebProgressListener::STATE_IS_WINDOW |
+          nsIWebProgressListener::STATE_IS_NETWORK;
+  for (uint32_t i = 0; i < list.Length(); ++i) {
+    list[i]->DoFireOnStateChange(this, request, flags, aStatus);
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////////
+// The following section contains support for nsIWebProgress and related stuff
+////////////////////////////////////////////////////////////////////////////////////
+
+NS_IMETHODIMP
+nsDocLoader::AddProgressListener(nsIWebProgressListener *aListener,
+                                 uint32_t aNotifyMask)
+{
+  if (mListenerInfoList.Contains(aListener)) {
+    // The listener is already registered!
+    return NS_ERROR_FAILURE;
+  }
+
+  nsWeakPtr listener = do_GetWeakReference(aListener);
+  if (!listener) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  return mListenerInfoList.AppendElement(nsListenerInfo(listener, aNotifyMask)) ?
+         NS_OK : NS_ERROR_OUT_OF_MEMORY;
+}
+
+NS_IMETHODIMP
+nsDocLoader::RemoveProgressListener(nsIWebProgressListener *aListener)
+{
+  return mListenerInfoList.RemoveElement(aListener) ? NS_OK : NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsDocLoader::GetDOMWindow(mozIDOMWindowProxy **aResult)
+{
+  return CallGetInterface(this, aResult);
+}
+
+NS_IMETHODIMP
+nsDocLoader::GetDOMWindowID(uint64_t *aResult)
+{
+  *aResult = 0;
+
+  nsCOMPtr<mozIDOMWindowProxy> window;
+  nsresult rv = GetDOMWindow(getter_AddRefs(window));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsPIDOMWindowOuter> piwindow = nsPIDOMWindowOuter::From(window);
+  NS_ENSURE_STATE(piwindow);
+
+  MOZ_ASSERT(piwindow->IsOuterWindow());
+  *aResult = piwindow->WindowID();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocLoader::GetIsTopLevel(bool *aResult)
+{
+  *aResult = false;
+
+  nsCOMPtr<mozIDOMWindowProxy> window;
+  GetDOMWindow(getter_AddRefs(window));
+  if (window) {
+    nsCOMPtr<nsPIDOMWindowOuter> piwindow = nsPIDOMWindowOuter::From(window);
+    NS_ENSURE_STATE(piwindow);
+
+    nsCOMPtr<nsPIDOMWindowOuter> topWindow = piwindow->GetTop();
+    *aResult = piwindow == topWindow;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocLoader::GetIsLoadingDocument(bool *aIsLoadingDocument)
+{
+  *aIsLoadingDocument = mIsLoadingDocument;
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsDocLoader::GetLoadType(uint32_t *aLoadType)
+{
+  *aLoadType = 0;
+
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+int64_t nsDocLoader::GetMaxTotalProgress()
+{
+  int64_t newMaxTotal = 0;
+
+  uint32_t count = mChildList.Length();
+  for (uint32_t i=0; i < count; i++)
+  {
+    int64_t individualProgress = 0;
+    nsIDocumentLoader* docloader = ChildAt(i);
+    if (docloader)
+    {
+      // Cast is safe since all children are nsDocLoader too
+      individualProgress = ((nsDocLoader *) docloader)->GetMaxTotalProgress();
+    }
+    if (individualProgress < int64_t(0)) // if one of the elements doesn't know it's size
+                                         // then none of them do
+    {
+       newMaxTotal = int64_t(-1);
+       break;
+    }
+    else
+     newMaxTotal += individualProgress;
+  }
+
+  int64_t progress = -1;
+  if (mMaxSelfProgress >= int64_t(0) && newMaxTotal >= int64_t(0))
+    progress = newMaxTotal + mMaxSelfProgress;
+
+  return progress;
+}
+
+////////////////////////////////////////////////////////////////////////////////////
+// The following section contains support for nsIProgressEventSink which is used to
+// pass progress and status between the actual request and the doc loader. The doc loader
+// then turns around and makes the right web progress calls based on this information.
+////////////////////////////////////////////////////////////////////////////////////
+
+NS_IMETHODIMP nsDocLoader::OnProgress(nsIRequest *aRequest, nsISupports* ctxt,
+                                      int64_t aProgress, int64_t aProgressMax)
+{
+  int64_t progressDelta = 0;
+
+  //
+  // Update the RequestInfo entry with the new progress data
+  //
+  if (nsRequestInfo* info = GetRequestInfo(aRequest)) {
+    // Update info->mCurrentProgress before we call FireOnStateChange,
+    // since that can make the "info" pointer invalid.
+    int64_t oldCurrentProgress = info->mCurrentProgress;
+    progressDelta = aProgress - oldCurrentProgress;
+    info->mCurrentProgress = aProgress;
+
+    // suppress sending STATE_TRANSFERRING if this is upload progress (see bug 240053)
+    if (!info->mUploading && (int64_t(0) == oldCurrentProgress) && (int64_t(0) == info->mMaxProgress)) {
+      //
+      // If we receive an OnProgress event from a toplevel channel that the URI Loader
+      // has not yet targeted, then we must suppress the event.  This is necessary to
+      // ensure that webprogresslisteners do not get confused when the channel is
+      // finally targeted.  See bug 257308.
+      //
+      nsLoadFlags lf = 0;
+      aRequest->GetLoadFlags(&lf);
+      if ((lf & nsIChannel::LOAD_DOCUMENT_URI) && !(lf & nsIChannel::LOAD_TARGETED)) {
+        MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+            ("DocLoader:%p Ignoring OnProgress while load is not targeted\n", this));
+        return NS_OK;
+      }
+
+      //
+      // This is the first progress notification for the entry.  If
+      // (aMaxProgress != -1) then the content-length of the data is known,
+      // so update mMaxSelfProgress...  Otherwise, set it to -1 to indicate
+      // that the content-length is no longer known.
+      //
+      if (aProgressMax != -1) {
+        mMaxSelfProgress  += aProgressMax;
+        info->mMaxProgress = aProgressMax;
+      } else {
+        mMaxSelfProgress   =  int64_t(-1);
+        info->mMaxProgress =  int64_t(-1);
+      }
+
+      // Send a STATE_TRANSFERRING notification for the request.
+      int32_t flags;
+
+      flags = nsIWebProgressListener::STATE_TRANSFERRING |
+              nsIWebProgressListener::STATE_IS_REQUEST;
+      //
+      // Move the WebProgress into the STATE_TRANSFERRING state if necessary...
+      //
+      if (mProgressStateFlags & nsIWebProgressListener::STATE_START) {
+        mProgressStateFlags = nsIWebProgressListener::STATE_TRANSFERRING;
+
+        // Send STATE_TRANSFERRING for the document too...
+        flags |= nsIWebProgressListener::STATE_IS_DOCUMENT;
+      }
+
+      FireOnStateChange(this, aRequest, flags, NS_OK);
+    }
+
+    // Update our overall current progress count.
+    mCurrentSelfProgress += progressDelta;
+  }
+  //
+  // The request is not part of the load group, so ignore its progress
+  // information...
+  //
+  else {
+#if defined(DEBUG)
+    nsAutoCString buffer;
+
+    GetURIStringFromRequest(aRequest, buffer);
+    MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+           ("DocLoader:%p OOPS - No Request Info for: %s\n",
+            this, buffer.get()));
+#endif /* DEBUG */
+
+    return NS_OK;
+  }
+
+  //
+  // Fire progress notifications out to any registered nsIWebProgressListeners
+  //
+  FireOnProgressChange(this, aRequest, aProgress, aProgressMax, progressDelta,
+                       mCurrentTotalProgress, mMaxTotalProgress);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsDocLoader::OnStatus(nsIRequest* aRequest, nsISupports* ctxt,
+                                        nsresult aStatus, const char16_t* aStatusArg)
+{
+  //
+  // Fire progress notifications out to any registered nsIWebProgressListeners
+  //
+  if (aStatus != NS_OK) {
+    // Remember the current status for this request
+    nsRequestInfo *info;
+    info = GetRequestInfo(aRequest);
+    if (info) {
+      bool uploading = (aStatus == NS_NET_STATUS_WRITING ||
+                        aStatus == NS_NET_STATUS_SENDING_TO);
+      // If switching from uploading to downloading (or vice versa), then we
+      // need to reset our progress counts.  This is designed with HTTP form
+      // submission in mind, where an upload is performed followed by download
+      // of possibly several documents.
+      if (info->mUploading != uploading) {
+        mCurrentSelfProgress  = mMaxSelfProgress  = 0;
+        mCurrentTotalProgress = mMaxTotalProgress = 0;
+        mCompletedTotalProgress = 0;
+        info->mUploading = uploading;
+        info->mCurrentProgress = 0;
+        info->mMaxProgress = 0;
+      }
+    }
+
+    nsCOMPtr<nsIStringBundleService> sbs =
+      mozilla::services::GetStringBundleService();
+    if (!sbs)
+      return NS_ERROR_FAILURE;
+    nsXPIDLString msg;
+    nsresult rv = sbs->FormatStatusMessage(aStatus, aStatusArg,
+                                           getter_Copies(msg));
+    if (NS_FAILED(rv))
+      return rv;
+
+    // Keep around the message. In case a request finishes, we need to make sure
+    // to send the status message of another request to our user to that we
+    // don't display, for example, "Transferring" messages for requests that are
+    // already done.
+    if (info) {
+      if (!info->mLastStatus) {
+        info->mLastStatus = new nsStatusInfo(aRequest);
+      } else {
+        // We're going to move it to the front of the list, so remove
+        // it from wherever it is now.
+        info->mLastStatus->remove();
+      }
+      info->mLastStatus->mStatusMessage = msg;
+      info->mLastStatus->mStatusCode = aStatus;
+      // Put the info at the front of the list
+      mStatusInfoList.insertFront(info->mLastStatus);
+    }
+    FireOnStatusChange(this, aRequest, aStatus, msg);
+  }
+  return NS_OK;
+}
+
+void nsDocLoader::ClearInternalProgress()
+{
+  ClearRequestInfoHash();
+
+  mCurrentSelfProgress  = mMaxSelfProgress  = 0;
+  mCurrentTotalProgress = mMaxTotalProgress = 0;
+  mCompletedTotalProgress = 0;
+
+  mProgressStateFlags = nsIWebProgressListener::STATE_STOP;
+}
+
+/**
+ * |_code| is executed for every listener matching |_flag|
+ * |listener| should be used inside |_code| as the nsIWebProgressListener var.
+ */
+#define NOTIFY_LISTENERS(_flag, _code)                     \
+PR_BEGIN_MACRO                                             \
+  nsCOMPtr<nsIWebProgressListener> listener;               \
+  ListenerArray::BackwardIterator iter(mListenerInfoList); \
+  while (iter.HasMore()) {                                 \
+    nsListenerInfo &info = iter.GetNext();                 \
+    if (!(info.mNotifyMask & (_flag))) {                   \
+      continue;                                            \
+    }                                                      \
+    listener = do_QueryReferent(info.mWeakListener);       \
+    if (!listener) {                                       \
+      iter.Remove();                                       \
+      continue;                                            \
+    }                                                      \
+    _code                                                  \
+  }                                                        \
+  mListenerInfoList.Compact();                             \
+PR_END_MACRO
+
+void nsDocLoader::FireOnProgressChange(nsDocLoader *aLoadInitiator,
+                                       nsIRequest *request,
+                                       int64_t aProgress,
+                                       int64_t aProgressMax,
+                                       int64_t aProgressDelta,
+                                       int64_t aTotalProgress,
+                                       int64_t aMaxTotalProgress)
+{
+  if (mIsLoadingDocument) {
+    mCurrentTotalProgress += aProgressDelta;
+    mMaxTotalProgress = GetMaxTotalProgress();
+
+    aTotalProgress    = mCurrentTotalProgress;
+    aMaxTotalProgress = mMaxTotalProgress;
+  }
+
+#if defined(DEBUG)
+  nsAutoCString buffer;
+
+  GetURIStringFromRequest(request, buffer);
+  MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+         ("DocLoader:%p: Progress (%s): curSelf: %d maxSelf: %d curTotal: %d maxTotal %d\n",
+          this, buffer.get(), aProgress, aProgressMax, aTotalProgress, aMaxTotalProgress));
+#endif /* DEBUG */
+
+  NOTIFY_LISTENERS(nsIWebProgress::NOTIFY_PROGRESS,
+    // XXX truncates 64-bit to 32-bit
+    listener->OnProgressChange(aLoadInitiator,request,
+                               int32_t(aProgress), int32_t(aProgressMax),
+                               int32_t(aTotalProgress), int32_t(aMaxTotalProgress));
+  );
+
+  // Pass the notification up to the parent...
+  if (mParent) {
+    mParent->FireOnProgressChange(aLoadInitiator, request,
+                                  aProgress, aProgressMax,
+                                  aProgressDelta,
+                                  aTotalProgress, aMaxTotalProgress);
+  }
+}
+
+void nsDocLoader::GatherAncestorWebProgresses(WebProgressList& aList)
+{
+  for (nsDocLoader* loader = this; loader; loader = loader->mParent) {
+    aList.AppendElement(loader);
+  }
+}
+
+void nsDocLoader::FireOnStateChange(nsIWebProgress *aProgress,
+                                    nsIRequest *aRequest,
+                                    int32_t aStateFlags,
+                                    nsresult aStatus)
+{
+  WebProgressList list;
+  GatherAncestorWebProgresses(list);
+  for (uint32_t i = 0; i < list.Length(); ++i) {
+    list[i]->DoFireOnStateChange(aProgress, aRequest, aStateFlags, aStatus);
+  }
+}
+
+void nsDocLoader::DoFireOnStateChange(nsIWebProgress * const aProgress,
+                                      nsIRequest * const aRequest,
+                                      int32_t &aStateFlags,
+                                      const nsresult aStatus)
+{
+  //
+  // Remove the STATE_IS_NETWORK bit if necessary.
+  //
+  // The rule is to remove this bit, if the notification has been passed
+  // up from a child WebProgress, and the current WebProgress is already
+  // active...
+  //
+  if (mIsLoadingDocument &&
+      (aStateFlags & nsIWebProgressListener::STATE_IS_NETWORK) &&
+      (this != aProgress)) {
+    aStateFlags &= ~nsIWebProgressListener::STATE_IS_NETWORK;
+  }
+
+  // Add the STATE_RESTORING bit if necessary.
+  if (mIsRestoringDocument)
+    aStateFlags |= nsIWebProgressListener::STATE_RESTORING;
+
+#if defined(DEBUG)
+  nsAutoCString buffer;
+
+  GetURIStringFromRequest(aRequest, buffer);
+  MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+         ("DocLoader:%p: Status (%s): code: %x\n",
+         this, buffer.get(), aStateFlags));
+#endif /* DEBUG */
+
+  NS_ASSERTION(aRequest, "Firing OnStateChange(...) notification with a NULL request!");
+
+  NOTIFY_LISTENERS(((aStateFlags >> 16) & nsIWebProgress::NOTIFY_STATE_ALL),
+    listener->OnStateChange(aProgress, aRequest, aStateFlags, aStatus);
+  );
+}
+
+
+
+void
+nsDocLoader::FireOnLocationChange(nsIWebProgress* aWebProgress,
+                                  nsIRequest* aRequest,
+                                  nsIURI *aUri,
+                                  uint32_t aFlags)
+{
+  NOTIFY_LISTENERS(nsIWebProgress::NOTIFY_LOCATION,
+    MOZ_LOG(gDocLoaderLog, LogLevel::Debug, ("DocLoader [%p] calling %p->OnLocationChange", this, listener.get()));
+    listener->OnLocationChange(aWebProgress, aRequest, aUri, aFlags);
+  );
+
+  // Pass the notification up to the parent...
+  if (mParent) {
+    mParent->FireOnLocationChange(aWebProgress, aRequest, aUri, aFlags);
+  }
+}
+
+void
+nsDocLoader::FireOnStatusChange(nsIWebProgress* aWebProgress,
+                                nsIRequest* aRequest,
+                                nsresult aStatus,
+                                const char16_t* aMessage)
+{
+  NOTIFY_LISTENERS(nsIWebProgress::NOTIFY_STATUS,
+    listener->OnStatusChange(aWebProgress, aRequest, aStatus, aMessage);
+  );
+
+  // Pass the notification up to the parent...
+  if (mParent) {
+    mParent->FireOnStatusChange(aWebProgress, aRequest, aStatus, aMessage);
+  }
+}
+
+bool
+nsDocLoader::RefreshAttempted(nsIWebProgress* aWebProgress,
+                              nsIURI *aURI,
+                              int32_t aDelay,
+                              bool aSameURI)
+{
+  /*
+   * Returns true if the refresh may proceed,
+   * false if the refresh should be blocked.
+   */
+  bool allowRefresh = true;
+
+  NOTIFY_LISTENERS(nsIWebProgress::NOTIFY_REFRESH,
+    nsCOMPtr<nsIWebProgressListener2> listener2 =
+      do_QueryReferent(info.mWeakListener);
+    if (!listener2)
+      continue;
+
+    bool listenerAllowedRefresh;
+    nsresult listenerRV = listener2->OnRefreshAttempted(
+        aWebProgress, aURI, aDelay, aSameURI, &listenerAllowedRefresh);
+    if (NS_FAILED(listenerRV))
+      continue;
+
+    allowRefresh = allowRefresh && listenerAllowedRefresh;
+  );
+
+  // Pass the notification up to the parent...
+  if (mParent) {
+    allowRefresh = allowRefresh &&
+      mParent->RefreshAttempted(aWebProgress, aURI, aDelay, aSameURI);
+  }
+
+  return allowRefresh;
+}
+
+nsresult nsDocLoader::AddRequestInfo(nsIRequest *aRequest)
+{
+  if (!mRequestInfoHash.Add(aRequest, mozilla::fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  return NS_OK;
+}
+
+void nsDocLoader::RemoveRequestInfo(nsIRequest *aRequest)
+{
+  mRequestInfoHash.Remove(aRequest);
+}
+
+nsDocLoader::nsRequestInfo* nsDocLoader::GetRequestInfo(nsIRequest* aRequest)
+{
+  return static_cast<nsRequestInfo*>(mRequestInfoHash.Search(aRequest));
+}
+
+void nsDocLoader::ClearRequestInfoHash(void)
+{
+  mRequestInfoHash.Clear();
+}
+
+int64_t nsDocLoader::CalculateMaxProgress()
+{
+  int64_t max = mCompletedTotalProgress;
+  for (auto iter = mRequestInfoHash.Iter(); !iter.Done(); iter.Next()) {
+    auto info = static_cast<const nsRequestInfo*>(iter.Get());
+
+    if (info->mMaxProgress < info->mCurrentProgress) {
+      return int64_t(-1);
+    }
+    max += info->mMaxProgress;
+  }
+  return max;
+}
+
+NS_IMETHODIMP nsDocLoader::AsyncOnChannelRedirect(nsIChannel *aOldChannel,
+                                                  nsIChannel *aNewChannel,
+                                                  uint32_t aFlags,
+                                                  nsIAsyncVerifyRedirectCallback *cb)
+{
+  if (aOldChannel)
+  {
+    nsLoadFlags loadFlags = 0;
+    int32_t stateFlags = nsIWebProgressListener::STATE_REDIRECTING |
+                         nsIWebProgressListener::STATE_IS_REQUEST;
+
+    aOldChannel->GetLoadFlags(&loadFlags);
+    // If the document channel is being redirected, then indicate that the
+    // document is being redirected in the notification...
+    if (loadFlags & nsIChannel::LOAD_DOCUMENT_URI)
+    {
+      stateFlags |= nsIWebProgressListener::STATE_IS_DOCUMENT;
+
+#if defined(DEBUG)
+      nsCOMPtr<nsIRequest> request(do_QueryInterface(aOldChannel));
+      NS_ASSERTION(request == mDocumentRequest, "Wrong Document Channel");
+#endif /* DEBUG */
+    }
+
+    OnRedirectStateChange(aOldChannel, aNewChannel, aFlags, stateFlags);
+    FireOnStateChange(this, aOldChannel, stateFlags, NS_OK);
+  }
+
+  cb->OnRedirectVerifyCallback(NS_OK);
+  return NS_OK;
+}
+
+/*
+ * Implementation of nsISecurityEventSink method...
+ */
+
+NS_IMETHODIMP nsDocLoader::OnSecurityChange(nsISupports * aContext,
+                                            uint32_t aState)
+{
+  //
+  // Fire progress notifications out to any registered nsIWebProgressListeners.
+  //
+
+  nsCOMPtr<nsIRequest> request = do_QueryInterface(aContext);
+  nsIWebProgress* webProgress = static_cast<nsIWebProgress*>(this);
+
+  NOTIFY_LISTENERS(nsIWebProgress::NOTIFY_SECURITY,
+    listener->OnSecurityChange(webProgress, request, aState);
+  );
+
+  // Pass the notification up to the parent...
+  if (mParent) {
+    mParent->OnSecurityChange(aContext, aState);
+  }
+  return NS_OK;
+}
+
+/*
+ * Implementation of nsISupportsPriority methods...
+ *
+ * The priority of the DocLoader _is_ the priority of its LoadGroup.
+ *
+ * XXX(darin): Once we start storing loadgroups in loadgroups, this code will
+ * go away.
+ */
+
+NS_IMETHODIMP nsDocLoader::GetPriority(int32_t *aPriority)
+{
+  nsCOMPtr<nsISupportsPriority> p = do_QueryInterface(mLoadGroup);
+  if (p)
+    return p->GetPriority(aPriority);
+
+  *aPriority = 0;
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsDocLoader::SetPriority(int32_t aPriority)
+{
+  MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+         ("DocLoader:%p: SetPriority(%d) called\n", this, aPriority));
+
+  nsCOMPtr<nsISupportsPriority> p = do_QueryInterface(mLoadGroup);
+  if (p)
+    p->SetPriority(aPriority);
+
+  NS_OBSERVER_ARRAY_NOTIFY_XPCOM_OBSERVERS(mChildList, nsDocLoader,
+                                           SetPriority, (aPriority));
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsDocLoader::AdjustPriority(int32_t aDelta)
+{
+  MOZ_LOG(gDocLoaderLog, LogLevel::Debug,
+         ("DocLoader:%p: AdjustPriority(%d) called\n", this, aDelta));
+
+  nsCOMPtr<nsISupportsPriority> p = do_QueryInterface(mLoadGroup);
+  if (p)
+    p->AdjustPriority(aDelta);
+
+  NS_OBSERVER_ARRAY_NOTIFY_XPCOM_OBSERVERS(mChildList, nsDocLoader,
+                                           AdjustPriority, (aDelta));
+
+  return NS_OK;
+}
+
+
+
+
+#if 0
+void nsDocLoader::DumpChannelInfo()
+{
+  nsChannelInfo *info;
+  int32_t i, count;
+  int32_t current=0, max=0;
+
+
+  printf("==== DocLoader=%x\n", this);
+
+  count = mChannelInfoList.Count();
+  for(i=0; i<count; i++) {
+    info = (nsChannelInfo *)mChannelInfoList.ElementAt(i);
+
+#if defined(DEBUG)
+    nsAutoCString buffer;
+    nsresult rv = NS_OK;
+    if (info->mURI) {
+      rv = info->mURI->GetSpec(buffer);
+    }
+
+    printf("  [%d] current=%d  max=%d [%s]\n", i,
+           info->mCurrentProgress,
+           info->mMaxProgress, buffer.get());
+#endif /* DEBUG */
+
+    current += info->mCurrentProgress;
+    if (max >= 0) {
+      if (info->mMaxProgress < info->mCurrentProgress) {
+        max = -1;
+      } else {
+        max += info->mMaxProgress;
+      }
+    }
+  }
+
+  printf("\nCurrent=%d   Total=%d\n====\n", current, max);
+}
+#endif /* 0 */
diff --git a/uriloader/base/nsDocLoader.h b/uriloader/base/nsDocLoader.h
new file mode 100644
index 000000000..481b1397b
--- /dev/null
+++ b/uriloader/base/nsDocLoader.h
@@ -0,0 +1,335 @@
+/* -*- Mode: C++; tab-width: 2; 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/. */
+
+/*
+*/
+
+#ifndef nsDocLoader_h__
+#define nsDocLoader_h__
+
+#include "nsIDocumentLoader.h"
+#include "nsIWebProgress.h"
+#include "nsIWebProgressListener.h"
+#include "nsIRequestObserver.h"
+#include "nsWeakReference.h"
+#include "nsILoadGroup.h"
+#include "nsCOMArray.h"
+#include "nsTObserverArray.h"
+#include "nsString.h"
+#include "nsIChannel.h"
+#include "nsIProgressEventSink.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIChannelEventSink.h"
+#include "nsISecurityEventSink.h"
+#include "nsISupportsPriority.h"
+#include "nsCOMPtr.h"
+#include "PLDHashTable.h"
+#include "nsAutoPtr.h"
+
+#include "mozilla/LinkedList.h"
+
+/****************************************************************************
+ * nsDocLoader implementation...
+ ****************************************************************************/
+
+#define NS_THIS_DOCLOADER_IMPL_CID                    \
+ { /* b4ec8387-98aa-4c08-93b6-6d23069c06f2 */         \
+     0xb4ec8387,                                      \
+     0x98aa,                                          \
+     0x4c08,                                          \
+     {0x93, 0xb6, 0x6d, 0x23, 0x06, 0x9c, 0x06, 0xf2} \
+ }
+
+class nsDocLoader : public nsIDocumentLoader,
+                    public nsIRequestObserver,
+                    public nsSupportsWeakReference,
+                    public nsIProgressEventSink,
+                    public nsIWebProgress,
+                    public nsIInterfaceRequestor,
+                    public nsIChannelEventSink,
+                    public nsISecurityEventSink,
+                    public nsISupportsPriority
+{
+public:
+    NS_DECLARE_STATIC_IID_ACCESSOR(NS_THIS_DOCLOADER_IMPL_CID)
+
+    nsDocLoader();
+
+    virtual MOZ_MUST_USE nsresult Init();
+
+    static already_AddRefed<nsDocLoader> GetAsDocLoader(nsISupports* aSupports);
+    // Needed to deal with ambiguous inheritance from nsISupports...
+    static nsISupports* GetAsSupports(nsDocLoader* aDocLoader) {
+        return static_cast<nsIDocumentLoader*>(aDocLoader);
+    }
+
+    // Add aDocLoader as a child to the docloader service.
+    static MOZ_MUST_USE nsresult AddDocLoaderAsChildOfRoot(nsDocLoader* aDocLoader);
+
+    NS_DECL_ISUPPORTS
+    NS_DECL_NSIDOCUMENTLOADER
+
+    // nsIProgressEventSink
+    NS_DECL_NSIPROGRESSEVENTSINK
+
+    NS_DECL_NSISECURITYEVENTSINK
+
+    // nsIRequestObserver methods: (for observing the load group)
+    NS_DECL_NSIREQUESTOBSERVER
+    NS_DECL_NSIWEBPROGRESS
+
+    NS_DECL_NSIINTERFACEREQUESTOR
+    NS_DECL_NSICHANNELEVENTSINK
+    NS_DECL_NSISUPPORTSPRIORITY
+
+    // Implementation specific methods...
+
+    // Remove aChild from our childlist.  This nulls out the child's mParent
+    // pointer.
+    MOZ_MUST_USE nsresult RemoveChildLoader(nsDocLoader *aChild);
+    // Add aChild to our child list.  This will set aChild's mParent pointer to
+    // |this|.
+    MOZ_MUST_USE nsresult AddChildLoader(nsDocLoader* aChild);
+    nsDocLoader* GetParent() const { return mParent; }
+
+    struct nsListenerInfo {
+      nsListenerInfo(nsIWeakReference *aListener, unsigned long aNotifyMask)
+        : mWeakListener(aListener),
+          mNotifyMask(aNotifyMask)
+      {
+      }
+
+      // Weak pointer for the nsIWebProgressListener...
+      nsWeakPtr mWeakListener;
+
+      // Mask indicating which notifications the listener wants to receive.
+      unsigned long mNotifyMask;
+    };
+
+protected:
+    virtual ~nsDocLoader();
+
+    virtual MOZ_MUST_USE nsresult SetDocLoaderParent(nsDocLoader * aLoader);
+
+    bool IsBusy();
+
+    void Destroy();
+    virtual void DestroyChildren();
+
+    nsIDocumentLoader* ChildAt(int32_t i) {
+        return mChildList.SafeElementAt(i, nullptr);
+    }
+
+    void FireOnProgressChange(nsDocLoader* aLoadInitiator,
+                              nsIRequest *request,
+                              int64_t aProgress,
+                              int64_t aProgressMax,
+                              int64_t aProgressDelta,
+                              int64_t aTotalProgress,
+                              int64_t aMaxTotalProgress);
+
+    // This should be at least 2 long since we'll generally always
+    // have the current page and the global docloader on the ancestor
+    // list.  But to deal with frames it's better to make it a bit
+    // longer, and it's always a stack temporary so there's no real
+    // reason not to.
+    typedef AutoTArray<RefPtr<nsDocLoader>, 8> WebProgressList;
+    void GatherAncestorWebProgresses(WebProgressList& aList);
+
+    void FireOnStateChange(nsIWebProgress *aProgress,
+                           nsIRequest* request,
+                           int32_t aStateFlags,
+                           nsresult aStatus);
+
+    // The guts of FireOnStateChange, but does not call itself on our ancestors.
+    // The arguments that are const are const so that we can detect cases when
+    // DoFireOnStateChange wants to propagate changes to the next web progress
+    // at compile time.  The ones that are not, are references so that such
+    // changes can be propagated.
+    void DoFireOnStateChange(nsIWebProgress * const aProgress,
+                             nsIRequest* const request,
+                             int32_t &aStateFlags,
+                             const nsresult aStatus);
+
+    void FireOnStatusChange(nsIWebProgress *aWebProgress,
+                            nsIRequest *aRequest,
+                            nsresult aStatus,
+                            const char16_t* aMessage);
+
+    void FireOnLocationChange(nsIWebProgress* aWebProgress,
+                              nsIRequest* aRequest,
+                              nsIURI *aUri,
+                              uint32_t aFlags);
+
+    MOZ_MUST_USE bool RefreshAttempted(nsIWebProgress* aWebProgress,
+                            nsIURI *aURI,
+                            int32_t aDelay,
+                            bool aSameURI);
+
+    // this function is overridden by the docshell, it is provided so that we
+    // can pass more information about redirect state (the normal OnStateChange
+    // doesn't get the new channel).
+    // @param aRedirectFlags The flags being sent to OnStateChange that
+    //                       indicate the type of redirect.
+    // @param aStateFlags    The channel flags normally sent to OnStateChange.
+    virtual void OnRedirectStateChange(nsIChannel* aOldChannel,
+                                       nsIChannel* aNewChannel,
+                                       uint32_t aRedirectFlags,
+                                       uint32_t aStateFlags) {}
+
+    void doStartDocumentLoad();
+    void doStartURLLoad(nsIRequest *request);
+    void doStopURLLoad(nsIRequest *request, nsresult aStatus);
+    void doStopDocumentLoad(nsIRequest *request, nsresult aStatus);
+
+    // Inform a parent docloader that aChild is about to call its onload
+    // handler.
+    MOZ_MUST_USE bool ChildEnteringOnload(nsIDocumentLoader* aChild) {
+        // It's ok if we're already in the list -- we'll just be in there twice
+        // and then the RemoveObject calls from ChildDoneWithOnload will remove
+        // us.
+        return mChildrenInOnload.AppendObject(aChild);
+    }
+
+    // Inform a parent docloader that aChild is done calling its onload
+    // handler.
+    void ChildDoneWithOnload(nsIDocumentLoader* aChild) {
+        mChildrenInOnload.RemoveObject(aChild);
+        DocLoaderIsEmpty(true);
+    }
+
+protected:
+    struct nsStatusInfo : public mozilla::LinkedListElement<nsStatusInfo>
+    {
+        nsString mStatusMessage;
+        nsresult mStatusCode;
+        // Weak mRequest is ok; we'll be told if it decides to go away.
+        nsIRequest * const mRequest;
+
+        explicit nsStatusInfo(nsIRequest* aRequest) :
+            mRequest(aRequest)
+        {
+            MOZ_COUNT_CTOR(nsStatusInfo);
+        }
+        ~nsStatusInfo()
+        {
+            MOZ_COUNT_DTOR(nsStatusInfo);
+        }
+    };
+
+    struct nsRequestInfo : public PLDHashEntryHdr
+    {
+        explicit nsRequestInfo(const void* key)
+            : mKey(key), mCurrentProgress(0), mMaxProgress(0), mUploading(false)
+            , mLastStatus(nullptr)
+        {
+            MOZ_COUNT_CTOR(nsRequestInfo);
+        }
+
+        ~nsRequestInfo()
+        {
+            MOZ_COUNT_DTOR(nsRequestInfo);
+        }
+
+        nsIRequest* Request() {
+            return static_cast<nsIRequest*>(const_cast<void*>(mKey));
+        }
+
+        const void* mKey; // Must be first for the PLDHashTable stubs to work
+        int64_t mCurrentProgress;
+        int64_t mMaxProgress;
+        bool mUploading;
+
+        nsAutoPtr<nsStatusInfo> mLastStatus;
+    };
+
+    static void RequestInfoHashInitEntry(PLDHashEntryHdr* entry, const void* key);
+    static void RequestInfoHashClearEntry(PLDHashTable* table, PLDHashEntryHdr* entry);
+
+    // IMPORTANT: The ownership implicit in the following member
+    // variables has been explicitly checked and set using nsCOMPtr
+    // for owning pointers and raw COM interface pointers for weak
+    // (ie, non owning) references. If you add any members to this
+    // class, please make the ownership explicit (pinkerton, scc).
+
+    nsCOMPtr<nsIRequest>       mDocumentRequest;       // [OWNER] ???compare with document
+
+    nsDocLoader*               mParent;                // [WEAK]
+
+    typedef nsAutoTObserverArray<nsListenerInfo, 8> ListenerArray;
+    ListenerArray              mListenerInfoList;
+
+    nsCOMPtr<nsILoadGroup>        mLoadGroup;
+    // We hold weak refs to all our kids
+    nsTObserverArray<nsDocLoader*> mChildList;
+
+    // The following member variables are related to the new nsIWebProgress
+    // feedback interfaces that travis cooked up.
+    int32_t mProgressStateFlags;
+
+    int64_t mCurrentSelfProgress;
+    int64_t mMaxSelfProgress;
+
+    int64_t mCurrentTotalProgress;
+    int64_t mMaxTotalProgress;
+
+    PLDHashTable mRequestInfoHash;
+    int64_t mCompletedTotalProgress;
+
+    mozilla::LinkedList<nsStatusInfo> mStatusInfoList;
+
+    /*
+     * This flag indicates that the loader is loading a document.  It is set
+     * from the call to LoadDocument(...) until the OnConnectionsComplete(...)
+     * notification is fired...
+     */
+    bool mIsLoadingDocument;
+
+    /* Flag to indicate that we're in the process of restoring a document. */
+    bool mIsRestoringDocument;
+
+    /* Flag to indicate that we're in the process of flushing layout
+       under DocLoaderIsEmpty() and should not do another flush. */
+    bool mDontFlushLayout;
+
+    /* Flag to indicate whether we should consider ourselves as currently
+       flushing layout for the purposes of IsBusy. For example, if Stop has
+       been called then IsBusy should return false even if we are still
+       flushing. */
+    bool mIsFlushingLayout;
+
+private:
+    static const PLDHashTableOps sRequestInfoHashOps;
+
+    // A list of kids that are in the middle of their onload calls and will let
+    // us know once they're done.  We don't want to fire onload for "normal"
+    // DocLoaderIsEmpty calls (those coming from requests finishing in our
+    // loadgroup) unless this is empty.
+    nsCOMArray<nsIDocumentLoader> mChildrenInOnload;
+
+    // DocLoaderIsEmpty should be called whenever the docloader may be empty.
+    // This method is idempotent and does nothing if the docloader is not in
+    // fact empty.  This method _does_ make sure that layout is flushed if our
+    // loadgroup has no active requests before checking for "real" emptiness if
+    // aFlushLayout is true.
+    void DocLoaderIsEmpty(bool aFlushLayout);
+
+    int64_t GetMaxTotalProgress();
+
+    nsresult AddRequestInfo(nsIRequest* aRequest);
+    void RemoveRequestInfo(nsIRequest* aRequest);
+    nsRequestInfo *GetRequestInfo(nsIRequest* aRequest);
+    void ClearRequestInfoHash();
+    int64_t CalculateMaxProgress();
+///    void DumpChannelInfo(void);
+
+    // used to clear our internal progress state between loads...
+    void ClearInternalProgress();
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsDocLoader, NS_THIS_DOCLOADER_IMPL_CID)
+
+#endif /* nsDocLoader_h__ */
diff --git a/uriloader/base/nsIContentHandler.idl b/uriloader/base/nsIContentHandler.idl
new file mode 100644
index 000000000..31ef87a8b
--- /dev/null
+++ b/uriloader/base/nsIContentHandler.idl
@@ -0,0 +1,35 @@
+/* -*- Mode: C++; tab-width: 2; 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 "nsISupports.idl"
+interface nsIRequest;
+interface nsIInterfaceRequestor;
+
+[scriptable, uuid(49439df2-b3d2-441c-bf62-866bdaf56fd2)]
+interface nsIContentHandler : nsISupports
+{
+  /**
+   * Tells the content handler to take over handling the content. If this
+   * function succeeds, the URI Loader will leave this request alone, ignoring
+   * progress notifications. Failure of this method will cause the request to be
+   * cancelled, unless the error code is NS_ERROR_WONT_HANDLE_CONTENT (see
+   * below).
+   *
+   * @param aWindowContext
+   *        Window context, used to get things like the current nsIDOMWindow
+   *        for this request. May be null.
+   * @param aContentType
+   *        The content type of aRequest
+   * @param aRequest
+   *        A request whose content type is already known.
+   *
+   * @throw NS_ERROR_WONT_HANDLE_CONTENT Indicates that this handler does not
+   *        want to handle this content. A different way for handling this
+   *        content should be tried.
+   */
+  void handleContent(in string aContentType,
+                     in nsIInterfaceRequestor aWindowContext,
+                     in nsIRequest aRequest);
+};
diff --git a/uriloader/base/nsIDocumentLoader.idl b/uriloader/base/nsIDocumentLoader.idl
new file mode 100644
index 000000000..3bd960ac8
--- /dev/null
+++ b/uriloader/base/nsIDocumentLoader.idl
@@ -0,0 +1,36 @@
+/* -*- Mode: C++; tab-width: 2; 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 "nsISupports.idl"
+interface nsILoadGroup;
+interface nsIChannel;
+interface nsIURI;
+interface nsIWebProgress;
+interface nsIRequest;
+
+/**
+ * An nsIDocumentLoader is an interface responsible for tracking groups of
+ * loads that belong together (images, external scripts, etc) and subdocuments
+ * (<iframe>, <frame>, etc). It is also responsible for sending
+ * nsIWebProgressListener notifications.
+ * XXXbz this interface should go away, we think...
+ */
+[scriptable, uuid(bbe961ee-59e9-42bb-be50-0331979bb79f)]
+interface nsIDocumentLoader : nsISupports
+{
+  // Stop all loads in the loadgroup of this docloader
+  void stop();
+
+  // XXXbz is this needed?  For embedding?  What this does is does is not
+  // defined by this interface!
+  readonly attribute nsISupports container;
+
+  // The loadgroup associated with this docloader
+  readonly attribute nsILoadGroup loadGroup;
+
+  // The defaultLoadRequest of the loadgroup associated with this docloader
+  readonly attribute nsIChannel documentChannel;
+};
+
diff --git a/uriloader/base/nsITransfer.idl b/uriloader/base/nsITransfer.idl
new file mode 100644
index 000000000..da34d4ac4
--- /dev/null
+++ b/uriloader/base/nsITransfer.idl
@@ -0,0 +1,106 @@
+/* -*- 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 "nsIWebProgressListener2.idl"
+
+interface nsIArray;
+interface nsIURI;
+interface nsICancelable;
+interface nsIMIMEInfo;
+interface nsIFile;
+
+[scriptable, uuid(37ec75d3-97ad-4da8-afaa-eabe5b4afd73)]
+interface nsITransfer : nsIWebProgressListener2 {
+
+    /**
+     * Initializes the transfer with certain properties.  This function must
+     * be called prior to accessing any properties on this interface.
+     *
+     * @param aSource The source URI of the transfer. Must not be null.
+     *
+     * @param aTarget The target URI of the transfer. Must not be null.
+     *
+     * @param aDisplayName The user-readable description of the transfer.
+     *                     Can be empty.
+     *
+     * @param aMIMEInfo The MIME info associated with the target,
+     *                  including MIME type and helper app when appropriate.
+     *                  This parameter is optional.
+     *
+     * @param startTime Time when the download started (ie, when the first
+     *                  response from the server was received)
+     *                  XXX presumably wbp and exthandler do this differently
+     *
+     * @param aTempFile The location of a temporary file; i.e. a file in which
+     *                  the received data will be stored, but which is not
+     *                  equal to the target file. (will be moved to the real
+     *                  target by the caller, when the download is finished)
+     *                  May be null.
+     *
+     * @param aCancelable An object that can be used to abort the download.
+     *                    Must not be null.
+     *                    Implementations are expected to hold a strong
+     *                    reference to this object until the download is
+     *                    finished, at which point they should release the
+     *                    reference.
+     *
+     * @param aIsPrivate Used to determine the privacy status of the new transfer.
+     *                   If true, indicates that the transfer was initiated from
+     *                   a source that desires privacy.
+     */
+    void init(in nsIURI aSource,
+              in nsIURI aTarget,
+              in AString aDisplayName,
+              in nsIMIMEInfo aMIMEInfo,
+              in PRTime startTime,
+              in nsIFile aTempFile,
+              in nsICancelable aCancelable,
+              in boolean aIsPrivate);
+
+    /*
+     * Used to notify the transfer object of the hash of the downloaded file.
+     * Must be called on the main thread, only after the download has finished
+     * successfully.
+     * @param aHash The SHA-256 hash in raw bytes of the downloaded file.
+     */
+    void setSha256Hash(in ACString aHash);
+
+    /*
+     * Used to notify the transfer object of the signature of the downloaded
+     * file.  Must be called on the main thread, only after the download has
+     * finished successfully.
+     * @param aSignatureInfo The nsIArray of nsIX509CertList of nsIX509Cert
+     *        certificates of the downloaded file.
+     */
+    void setSignatureInfo(in nsIArray aSignatureInfo);
+
+    /*
+     * Used to notify the transfer object of the redirects associated with the
+     * channel that terminated in the downloaded file.  Must be called on the
+     * main thread, only after the download has finished successfully.
+     * @param aRedirects The nsIArray of nsIPrincipal of redirected URIs
+     *        associated with the downloaded file.
+     */
+    void setRedirects(in nsIArray aRedirects);
+};
+
+%{C++
+/**
+ * A component with this contract ID will be created each time a download is
+ * started, and nsITransfer::Init will be called on it and an observer will be set.
+ *
+ * Notifications of the download progress will happen via
+ * nsIWebProgressListener/nsIWebProgressListener2.
+ *
+ * INTERFACES THAT MUST BE IMPLEMENTED:
+ *   nsITransfer
+ *   nsIWebProgressListener
+ *   nsIWebProgressListener2
+ *
+ * XXX move this to nsEmbedCID.h once the interfaces (and the contract ID) are
+ * frozen.
+ */
+#define NS_TRANSFER_CONTRACTID "@mozilla.org/transfer;1"
+%}
diff --git a/uriloader/base/nsIURIContentListener.idl b/uriloader/base/nsIURIContentListener.idl
new file mode 100644
index 000000000..9008cb61e
--- /dev/null
+++ b/uriloader/base/nsIURIContentListener.idl
@@ -0,0 +1,135 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "nsISupports.idl"
+
+interface nsIRequest;
+interface nsIStreamListener;
+interface nsIURI;
+
+/**
+ * nsIURIContentListener is an interface used by components which
+ * want to know (and have a chance to handle) a particular content type.
+ * Typical usage scenarios will include running applications which register
+ * a nsIURIContentListener for each of its content windows with the uri
+ * dispatcher service. 
+ */
+[scriptable, uuid(10a28f38-32e8-4c63-8aa1-12eaaebc369a)]
+interface nsIURIContentListener : nsISupports
+{
+ /**
+  * Gives the original content listener first crack at stopping a load before
+  * it happens.
+  *
+  * @param aURI   URI that is being opened.
+  *
+  * @return       <code>false</code> if the load can continue;
+  *               <code>true</code> if the open should be aborted.
+  */
+  boolean onStartURIOpen(in nsIURI aURI);
+
+ /**
+  * Notifies the content listener to hook up an nsIStreamListener capable of
+  * consuming the data stream.
+  *
+  * @param aContentType         Content type of the data.
+  * @param aIsContentPreferred  Indicates whether the content should be
+  *                             preferred by this listener.
+  * @param aRequest             Request that is providing the data.
+  * @param aContentHandler      nsIStreamListener that will consume the data.
+  *                             This should be set to <code>nullptr</code> if
+  *                             this content listener can't handle the content
+  *                             type; in this case, doContent should also fail
+  *                             (i.e., return failure nsresult).
+  *
+  * @return                     <code>true</code> if the load should
+  *                             be aborted and consumer wants to
+  *                             handle the load completely by itself.  This
+  *                             causes the URI Loader do nothing else...
+  *                             <code>false</code> if the URI Loader should
+  *                             continue handling the load and call the
+  *                             returned streamlistener's methods. 
+  */
+  boolean doContent(in ACString aContentType,
+                    in boolean aIsContentPreferred,
+                    in nsIRequest aRequest,
+                    out nsIStreamListener aContentHandler);
+
+ /**
+  * When given a uri to dispatch, if the URI is specified as 'preferred 
+  * content' then the uri loader tries to find a preferred content handler
+  * for the content type. The thought is that many content listeners may
+  * be able to handle the same content type if they have to. i.e. the mail
+  * content window can handle text/html just like a browser window content
+  * listener. However, if the user clicks on a link with text/html content,
+  * then the browser window should handle that content and not the mail
+  * window where the user may have clicked the link.  This is the difference
+  * between isPreferred and canHandleContent.
+  *
+  * @param aContentType         Content type of the data.
+  * @param aDesiredContentType  Indicates that aContentType must be converted
+  *                             to aDesiredContentType before processing the
+  *                             data.  This causes a stream converted to be
+  *                             inserted into the nsIStreamListener chain.
+  *                             This argument can be <code>nullptr</code> if
+  *                             the content should be consumed directly as
+  *                             aContentType.
+  *
+  * @return                     <code>true</code> if this is a preferred
+  *                             content handler for aContentType;
+  *                             <code>false<code> otherwise.
+  */
+  boolean isPreferred(in string aContentType, out string aDesiredContentType);
+
+ /**
+  * When given a uri to dispatch, if the URI is not specified as 'preferred
+  * content' then the uri loader calls canHandleContent to see if the content
+  * listener is capable of handling the content.
+  *
+  * @param aContentType         Content type of the data.
+  * @param aIsContentPreferred  Indicates whether the content should be
+  *                             preferred by this listener.
+  * @param aDesiredContentType  Indicates that aContentType must be converted
+  *                             to aDesiredContentType before processing the
+  *                             data.  This causes a stream converted to be
+  *                             inserted into the nsIStreamListener chain.
+  *                             This argument can be <code>nullptr</code> if
+  *                             the content should be consumed directly as
+  *                             aContentType.
+  *
+  * @return                     <code>true</code> if the data can be consumed.
+  *                             <code>false</code> otherwise.
+  *
+  * Note: I really envision canHandleContent as a method implemented
+  * by the docshell as the implementation is generic to all doc
+  * shells. The isPreferred decision is a decision made by a top level
+  * application content listener that sits at the top of the docshell
+  * hierarchy.
+  */
+  boolean canHandleContent(in string aContentType, 
+                           in boolean aIsContentPreferred, 
+                           out string aDesiredContentType);
+
+ /**
+  * The load context associated with a particular content listener.
+  * The URI Loader stores and accesses this value as needed.
+  */
+  attribute nsISupports loadCookie;
+
+ /**
+  * The parent content listener if this particular listener is part of a chain
+  * of content listeners (i.e. a docshell!)
+  *
+  * @note If this attribute is set to an object that implements
+  *       nsISupportsWeakReference, the implementation should get the
+  *       nsIWeakReference and hold that.  Otherwise, the implementation
+  *       should not refcount this interface; it should assume that a non
+  *       null value is always valid.  In that case, the caller is
+  *       responsible for explicitly setting this value back to null if the
+  *       parent content listener is destroyed.
+  */
+  attribute nsIURIContentListener parentContentListener;
+};
+
diff --git a/uriloader/base/nsIURILoader.idl b/uriloader/base/nsIURILoader.idl
new file mode 100644
index 000000000..74f21e363
--- /dev/null
+++ b/uriloader/base/nsIURILoader.idl
@@ -0,0 +1,140 @@
+/* -*- Mode: C++; tab-width: 2; 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 "nsISupports.idl"
+
+interface nsIURIContentListener;
+interface nsIURI;
+interface nsILoadGroup;
+interface nsIProgressEventSink;
+interface nsIChannel;
+interface nsIRequest;
+interface nsIStreamListener;
+interface nsIInputStream;
+interface nsIInterfaceRequestor;
+
+/**
+ * The uri dispatcher is responsible for taking uri's, determining
+ * the content and routing the opened url to the correct content 
+ * handler. 
+ *
+ * When you encounter a url you want to open, you typically call 
+ * openURI, passing it the content listener for the window the uri is 
+ * originating from. The uri dispatcher opens the url to discover the 
+ * content type. It then gives the content listener first crack at 
+ * handling the content. If it doesn't want it, the dispatcher tries
+ * to hand it off one of the registered content listeners. This allows
+ * running applications the chance to jump in and handle the content.
+ *
+ * If that also fails, then the uri dispatcher goes to the registry
+ * looking for the preferred content handler for the content type
+ * of the uri. The content handler may create an app instance
+ * or it may hand the contents off to a platform specific plugin
+ * or helper app. Or it may hand the url off to an OS registered 
+ * application. 
+ */
+[scriptable, uuid(8762c4e7-be35-4958-9b81-a05685bb516d)]
+interface nsIURILoader : nsISupports
+{
+  /**
+   * @name Flags for opening URIs.
+   */
+  /* @{ */
+  /**
+   * Should the content be displayed in a container that prefers the
+   * content-type, or will any container do.
+   */
+  const unsigned long IS_CONTENT_PREFERRED = 1 << 0;
+  /**
+   * If this flag is set, only the listener of the specified window context will
+   * be considered for content handling; if it refuses the load, an error will
+   * be indicated.
+   */
+  const unsigned long DONT_RETARGET        = 1 << 1;
+  /* @} */
+
+  /**
+   * As applications such as messenger and the browser are instantiated,
+   * they register content listener's with the uri dispatcher corresponding
+   * to content windows within that application. 
+   *
+   * Note to self: we may want to optimize things a bit more by requiring
+   * the content types the registered content listener cares about.
+   *
+   * @param aContentListener
+   *        The listener to register. This listener must implement
+   *        nsISupportsWeakReference.
+   *
+   * @see the nsIURILoader class description
+   */
+  void registerContentListener   (in nsIURIContentListener aContentListener);
+  void unRegisterContentListener (in nsIURIContentListener aContentListener);
+
+  /**
+   * OpenURI requires the following parameters.....
+   * @param aChannel
+   *        The channel that should be opened. This must not be asyncOpen'd yet!
+   *        If a loadgroup is set on the channel, it will get replaced with a
+   *        different one.
+   * @param aFlags
+   *        Combination (bitwise OR) of the flags specified above. 0 indicates
+   *        default handling.
+   * @param aWindowContext
+   *        If you are running the url from a doc shell or a web shell, this is
+   *        your window context. If you have a content listener you want to
+   *        give first crack to, the uri loader needs to be able to get it
+   *        from the window context. We will also be using the window context
+   *        to get at the progress event sink interface.
+   *        <b>Must not be null!</b>
+   */ 
+  void openURI(in nsIChannel aChannel,
+               in unsigned long aFlags,
+               in nsIInterfaceRequestor aWindowContext);
+
+  /**
+   * Loads data from a channel. This differs from openURI in that the channel
+   * may already be opened, and that it returns a stream listener into which the
+   * caller should pump data. The caller is responsible for opening the channel
+   * and pumping the channel's data into the returned stream listener.
+   *
+   * Note: If the channel already has a loadgroup, it will be replaced with the
+   * window context's load group, or null if the context doesn't have one.
+   *
+   * If the window context's nsIURIContentListener refuses the load immediately
+   * (e.g. in nsIURIContentListener::onStartURIOpen), this method will return
+   * NS_ERROR_WONT_HANDLE_CONTENT. At that point, the caller should probably
+   * cancel the channel if it's already open (this method will not cancel the
+   * channel).
+   *
+   * If flags include DONT_RETARGET, and the content listener refuses the load
+   * during onStartRequest (e.g. in canHandleContent/isPreferred), then the
+   * returned stream listener's onStartRequest method will return
+   * NS_ERROR_WONT_HANDLE_CONTENT.
+   *
+   * @param aChannel
+   *        The channel that should be loaded. The channel may already be
+   *        opened. It must not be closed (i.e. this must be called before the
+   *        channel calls onStopRequest on its stream listener).
+   * @param aFlags
+   *        Combination (bitwise OR) of the flags specified above. 0 indicates
+   *        default handling.
+   * @param aWindowContext
+   *        If you are running the url from a doc shell or a web shell, this is
+   *        your window context. If you have a content listener you want to
+   *        give first crack to, the uri loader needs to be able to get it
+   *        from the window context. We will also be using the window context
+   *        to get at the progress event sink interface.
+   *        <b>Must not be null!</b>
+   */ 
+  nsIStreamListener openChannel(in nsIChannel aChannel,
+                                in unsigned long aFlags,
+                                in nsIInterfaceRequestor aWindowContext);
+
+  /**
+   * Stops an in progress load
+   */
+  void stop(in nsISupports aLoadCookie);
+};
+
diff --git a/uriloader/base/nsIWebProgress.idl b/uriloader/base/nsIWebProgress.idl
new file mode 100644
index 000000000..9d17d0a4d
--- /dev/null
+++ b/uriloader/base/nsIWebProgress.idl
@@ -0,0 +1,153 @@
+/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * 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 "nsISupports.idl"
+
+interface mozIDOMWindowProxy;
+interface nsIWebProgressListener;
+
+/**
+ * The nsIWebProgress interface is used to add or remove nsIWebProgressListener
+ * instances to observe the loading of asynchronous requests (usually in the
+ * context of a DOM window).
+ *
+ * nsIWebProgress instances may be arranged in a parent-child configuration,
+ * corresponding to the parent-child configuration of their respective DOM
+ * windows.  However, in some cases a nsIWebProgress instance may not have an
+ * associated DOM window.  The parent-child relationship of nsIWebProgress
+ * instances is not made explicit by this interface, but the relationship may
+ * exist in some implementations.
+ *
+ * A nsIWebProgressListener instance receives notifications for the
+ * nsIWebProgress instance to which it added itself, and it may also receive
+ * notifications from any nsIWebProgress instances that are children of that
+ * nsIWebProgress instance.
+ */
+[scriptable, uuid(c4d64640-b332-4db6-a2a5-e08566000dc9)]
+interface nsIWebProgress : nsISupports
+{
+  /**
+   * The following flags may be combined to form the aNotifyMask parameter for
+   * the addProgressListener method.  They limit the set of events that are
+   * delivered to an nsIWebProgressListener instance.
+   */
+
+  /**
+   * These flags indicate the state transistions to observe, corresponding to
+   * nsIWebProgressListener::onStateChange.
+   *
+   * NOTIFY_STATE_REQUEST
+   *   Only receive the onStateChange event if the aStateFlags parameter
+   *   includes nsIWebProgressListener::STATE_IS_REQUEST.
+   *
+   * NOTIFY_STATE_DOCUMENT
+   *   Only receive the onStateChange event if the aStateFlags parameter
+   *   includes nsIWebProgressListener::STATE_IS_DOCUMENT.
+   *
+   * NOTIFY_STATE_NETWORK
+   *   Only receive the onStateChange event if the aStateFlags parameter
+   *   includes nsIWebProgressListener::STATE_IS_NETWORK.
+   *
+   * NOTIFY_STATE_WINDOW
+   *   Only receive the onStateChange event if the aStateFlags parameter
+   *   includes nsIWebProgressListener::STATE_IS_WINDOW.
+   *
+   * NOTIFY_STATE_ALL
+   *   Receive all onStateChange events.
+   */
+  const unsigned long NOTIFY_STATE_REQUEST  = 0x00000001;
+  const unsigned long NOTIFY_STATE_DOCUMENT = 0x00000002;
+  const unsigned long NOTIFY_STATE_NETWORK  = 0x00000004;
+  const unsigned long NOTIFY_STATE_WINDOW   = 0x00000008;
+  const unsigned long NOTIFY_STATE_ALL      = 0x0000000f;
+
+  /**
+   * These flags indicate the other events to observe, corresponding to the
+   * other four methods defined on nsIWebProgressListener.
+   *
+   * NOTIFY_PROGRESS
+   *   Receive onProgressChange events.
+   *
+   * NOTIFY_STATUS
+   *   Receive onStatusChange events.
+   *
+   * NOTIFY_SECURITY
+   *   Receive onSecurityChange events.
+   *
+   * NOTIFY_LOCATION
+   *   Receive onLocationChange events.
+   *
+   * NOTIFY_REFRESH
+   *   Receive onRefreshAttempted events.
+   *   This is defined on nsIWebProgressListener2.
+   */
+  const unsigned long NOTIFY_PROGRESS       = 0x00000010;
+  const unsigned long NOTIFY_STATUS         = 0x00000020;
+  const unsigned long NOTIFY_SECURITY       = 0x00000040;
+  const unsigned long NOTIFY_LOCATION       = 0x00000080;
+  const unsigned long NOTIFY_REFRESH        = 0x00000100;
+
+  /**
+   * This flag enables all notifications.
+   */
+  const unsigned long NOTIFY_ALL            = 0x000001ff;
+
+  /**
+   * Registers a listener to receive web progress events.
+   *
+   * @param aListener
+   *        The listener interface to be called when a progress event occurs.
+   *        This object must also implement nsISupportsWeakReference.
+   * @param aNotifyMask
+   *        The types of notifications to receive.
+   *
+   * @throw NS_ERROR_INVALID_ARG
+   *        Indicates that aListener was either null or that it does not
+   *        support weak references.
+   * @throw NS_ERROR_FAILURE
+   *        Indicates that aListener was already registered.
+   */
+  void addProgressListener(in nsIWebProgressListener aListener,
+                           in unsigned long aNotifyMask);
+
+  /**
+   * Removes a previously registered listener of progress events.
+   *
+   * @param aListener
+   *        The listener interface previously registered with a call to
+   *        addProgressListener.
+   *
+   * @throw NS_ERROR_FAILURE
+   *        Indicates that aListener was not registered.
+   */
+  void removeProgressListener(in nsIWebProgressListener aListener);
+
+  /**
+   * The DOM window associated with this nsIWebProgress instance.
+   *
+   * @throw NS_ERROR_FAILURE
+   *        Indicates that there is no associated DOM window.
+   */
+  readonly attribute mozIDOMWindowProxy DOMWindow;
+  readonly attribute uint64_t DOMWindowID;
+
+  /**
+   * Indicates whether DOMWindow.top == DOMWindow.
+   */
+  readonly attribute boolean isTopLevel;
+
+  /**
+   * Indicates whether or not a document is currently being loaded
+   * in the context of this nsIWebProgress instance.
+   */
+  readonly attribute boolean isLoadingDocument;
+
+  /**
+   * Contains a load type as specified by the load* constants in
+   * nsIDocShellLoadInfo.idl.
+   */
+  readonly attribute unsigned long loadType;
+};
diff --git a/uriloader/base/nsIWebProgressListener.idl b/uriloader/base/nsIWebProgressListener.idl
new file mode 100644
index 000000000..714b931a3
--- /dev/null
+++ b/uriloader/base/nsIWebProgressListener.idl
@@ -0,0 +1,425 @@
+/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * 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 "nsISupports.idl"
+
+interface nsIWebProgress;
+interface nsIRequest;
+interface nsIURI;
+
+/**
+ * The nsIWebProgressListener interface is implemented by clients wishing to
+ * listen in on the progress associated with the loading of asynchronous
+ * requests in the context of a nsIWebProgress instance as well as any child
+ * nsIWebProgress instances.  nsIWebProgress.idl describes the parent-child
+ * relationship of nsIWebProgress instances.
+ */
+[scriptable, uuid(a9df523b-efe2-421e-9d8e-3d7f807dda4c)]
+interface nsIWebProgressListener : nsISupports
+{
+  /**
+   * State Transition Flags
+   *
+   * These flags indicate the various states that requests may transition
+   * through as they are being loaded.  These flags are mutually exclusive.
+   *
+   * For any given request, onStateChange is called once with the STATE_START
+   * flag, zero or more times with the STATE_TRANSFERRING flag or once with the
+   * STATE_REDIRECTING flag, and then finally once with the STATE_STOP flag.
+   * NOTE: For document requests, a second STATE_STOP is generated (see the
+   * description of STATE_IS_WINDOW for more details).
+   *
+   * STATE_START
+   *   This flag indicates the start of a request.  This flag is set when a
+   *   request is initiated.  The request is complete when onStateChange is
+   *   called for the same request with the STATE_STOP flag set.
+   *
+   * STATE_REDIRECTING
+   *   This flag indicates that a request is being redirected.  The request
+   *   passed to onStateChange is the request that is being redirected.  When a
+   *   redirect occurs, a new request is generated automatically to process the
+   *   new request.  Expect a corresponding STATE_START event for the new
+   *   request, and a STATE_STOP for the redirected request.
+   *
+   * STATE_TRANSFERRING
+   *   This flag indicates that data for a request is being transferred to an
+   *   end consumer.  This flag indicates that the request has been targeted,
+   *   and that the user may start seeing content corresponding to the request.
+   *
+   * STATE_NEGOTIATING
+   *   This flag is not used.
+   *
+   * STATE_STOP
+   *   This flag indicates the completion of a request.  The aStatus parameter
+   *   to onStateChange indicates the final status of the request.
+   */
+  const unsigned long STATE_START          = 0x00000001;
+  const unsigned long STATE_REDIRECTING    = 0x00000002;
+  const unsigned long STATE_TRANSFERRING   = 0x00000004;
+  const unsigned long STATE_NEGOTIATING    = 0x00000008;
+  const unsigned long STATE_STOP           = 0x00000010;
+
+
+  /**
+   * State Type Flags
+   *
+   * These flags further describe the entity for which the state transition is
+   * occuring.  These flags are NOT mutually exclusive (i.e., an onStateChange
+   * event may indicate some combination of these flags).
+   *
+   * STATE_IS_REQUEST
+   *   This flag indicates that the state transition is for a request, which
+   *   includes but is not limited to document requests.  (See below for a
+   *   description of document requests.)  Other types of requests, such as
+   *   requests for inline content (e.g., images and stylesheets) are
+   *   considered normal requests.
+   *
+   * STATE_IS_DOCUMENT
+   *   This flag indicates that the state transition is for a document request.
+   *   This flag is set in addition to STATE_IS_REQUEST.  A document request
+   *   supports the nsIChannel interface and its loadFlags attribute includes
+   *   the nsIChannel::LOAD_DOCUMENT_URI flag.
+   * 
+   *   A document request does not complete until all requests associated with
+   *   the loading of its corresponding document have completed.  This includes
+   *   other document requests (e.g., corresponding to HTML <iframe> elements).
+   *   The document corresponding to a document request is available via the
+   *   DOMWindow attribute of onStateChange's aWebProgress parameter.
+   *
+   * STATE_IS_NETWORK
+   *   This flag indicates that the state transition corresponds to the start
+   *   or stop of activity in the indicated nsIWebProgress instance.  This flag
+   *   is accompanied by either STATE_START or STATE_STOP, and it may be
+   *   combined with other State Type Flags.
+   *
+   *   Unlike STATE_IS_WINDOW, this flag is only set when activity within the
+   *   nsIWebProgress instance being observed starts or stops.  If activity
+   *   only occurs in a child nsIWebProgress instance, then this flag will be
+   *   set to indicate the start and stop of that activity.
+   *
+   *   For example, in the case of navigation within a single frame of a HTML
+   *   frameset, a nsIWebProgressListener instance attached to the
+   *   nsIWebProgress of the frameset window will receive onStateChange calls
+   *   with the STATE_IS_NETWORK flag set to indicate the start and stop of
+   *   said navigation.  In other words, an observer of an outer window can
+   *   determine when activity, that may be constrained to a child window or
+   *   set of child windows, starts and stops.
+   *
+   * STATE_IS_WINDOW
+   *   This flag indicates that the state transition corresponds to the start
+   *   or stop of activity in the indicated nsIWebProgress instance.  This flag
+   *   is accompanied by either STATE_START or STATE_STOP, and it may be
+   *   combined with other State Type Flags.
+   *
+   *   This flag is similar to STATE_IS_DOCUMENT.  However, when a document
+   *   request completes, two onStateChange calls with STATE_STOP are
+   *   generated.  The document request is passed as aRequest to both calls.
+   *   The first has STATE_IS_REQUEST and STATE_IS_DOCUMENT set, and the second
+   *   has the STATE_IS_WINDOW flag set (and possibly the STATE_IS_NETWORK flag
+   *   set as well -- see above for a description of when the STATE_IS_NETWORK
+   *   flag may be set).  This second STATE_STOP event may be useful as a way
+   *   to partition the work that occurs when a document request completes.
+   */
+  const unsigned long STATE_IS_REQUEST     = 0x00010000;
+  const unsigned long STATE_IS_DOCUMENT    = 0x00020000;
+  const unsigned long STATE_IS_NETWORK     = 0x00040000;
+  const unsigned long STATE_IS_WINDOW      = 0x00080000;
+
+
+  /**
+   * State Modifier Flags
+   *
+   * These flags further describe the transition which is occuring.  These
+   * flags are NOT mutually exclusive (i.e., an onStateChange event may
+   * indicate some combination of these flags).
+   *
+   * STATE_RESTORING
+   *   This flag indicates that the state transition corresponds to the start
+   *   or stop of activity for restoring a previously-rendered presentation.
+   *   As such, there is no actual network activity associated with this
+   *   request, and any modifications made to the document or presentation
+   *   when it was originally loaded will still be present.
+   */
+  const unsigned long STATE_RESTORING      = 0x01000000;
+
+  /**
+   * State Security Flags
+   *
+   * These flags describe the security state reported by a call to the
+   * onSecurityChange method.  These flags are mutually exclusive.
+   *
+   * STATE_IS_INSECURE
+   *   This flag indicates that the data corresponding to the request
+   *   was received over an insecure channel.
+   *
+   * STATE_IS_BROKEN
+   *   This flag indicates an unknown security state.  This may mean that the
+   *   request is being loaded as part of a page in which some content was
+   *   received over an insecure channel.
+   *
+   * STATE_IS_SECURE
+   *   This flag indicates that the data corresponding to the request was
+   *   received over a secure channel.  The degree of security is expressed by
+   *   STATE_SECURE_HIGH, STATE_SECURE_MED, or STATE_SECURE_LOW.
+   */
+  const unsigned long STATE_IS_INSECURE     = 0x00000004;
+  const unsigned long STATE_IS_BROKEN       = 0x00000001;
+  const unsigned long STATE_IS_SECURE       = 0x00000002;
+
+  /**
+   * Mixed active content flags
+   *
+   * May be set in addition to the State Security Flags, to indicate that
+   * mixed active content has been encountered.
+   *
+   * STATE_BLOCKED_MIXED_ACTIVE_CONTENT
+   *   Mixed active content has been blocked from loading.
+   *
+   * STATE_LOADED_MIXED_ACTIVE_CONTENT
+   *   Mixed active content has been loaded. State should be STATE_IS_BROKEN.
+   */
+  const unsigned long STATE_BLOCKED_MIXED_ACTIVE_CONTENT  = 0x00000010;
+  const unsigned long STATE_LOADED_MIXED_ACTIVE_CONTENT   = 0x00000020;
+
+  /**
+   * Mixed display content flags
+   *
+   * May be set in addition to the State Security Flags, to indicate that
+   * mixed display content has been encountered.
+   *
+   * STATE_BLOCKED_MIXED_DISPLAY_CONTENT
+   *   Mixed display content has been blocked from loading.
+   *
+   * STATE_LOADED_MIXED_DISPLAY_CONTENT
+   *   Mixed display content has been loaded. State should be STATE_IS_BROKEN.
+   */
+  const unsigned long STATE_BLOCKED_MIXED_DISPLAY_CONTENT = 0x00000100;
+  const unsigned long STATE_LOADED_MIXED_DISPLAY_CONTENT  = 0x00000200;
+
+   /**
+   * Tracking content flags
+   *
+   * May be set in addition to the State security Flags, to indicate that
+   * tracking content has been encountered.
+   *
+   * STATE_BLOCKED_TRACKING_CONTENT
+   *   Tracking content has been blocked from loading.
+   *
+   * STATE_LOADED_TRACKING_CONTENT
+   *   Tracking content has been loaded.
+   */
+  const unsigned long STATE_BLOCKED_TRACKING_CONTENT = 0x00001000;
+  const unsigned long STATE_LOADED_TRACKING_CONTENT  = 0x00002000;
+
+  /**
+   * Security Strength Flags
+   *
+   * These flags describe the security strength and accompany STATE_IS_SECURE
+   * in a call to the onSecurityChange method.  These flags are mutually
+   * exclusive.
+   *
+   * These flags are not meant to provide a precise description of data
+   * transfer security.  These are instead intended as a rough indicator that
+   * may be used to, for example, color code a security indicator or otherwise
+   * provide basic data transfer security feedback to the user.
+   *
+   * STATE_SECURE_HIGH
+   *   This flag indicates a high degree of security.
+   *
+   * STATE_SECURE_MED
+   *   This flag indicates a medium degree of security.
+   *
+   * STATE_SECURE_LOW
+   *   This flag indicates a low degree of security.
+   */
+  const unsigned long STATE_SECURE_HIGH     = 0x00040000;
+  const unsigned long STATE_SECURE_MED      = 0x00010000;
+  const unsigned long STATE_SECURE_LOW      = 0x00020000;
+
+  /**
+    * State bits for EV == Extended Validation == High Assurance
+    *
+    * These flags describe the level of identity verification
+    * in a call to the onSecurityChange method. 
+    *
+    * STATE_IDENTITY_EV_TOPLEVEL
+    *   The topmost document uses an EV cert.
+    *   NOTE: Available since Gecko 1.9
+    */
+
+  const unsigned long STATE_IDENTITY_EV_TOPLEVEL    = 0x00100000;
+
+  /**
+    * Broken state flags
+    *
+    * These flags describe the reason of the broken state.
+    *
+    * STATE_USES_SSL_3
+    *   The topmost document uses SSL 3.0.
+    *
+    * STATE_USES_WEAK_CRYPTO
+    *   The topmost document uses a weak cipher suite such as RC4.
+    *
+    * STATE_CERT_USER_OVERRIDDEN
+    *   The user has added a security exception for the site.
+    */
+  const unsigned long STATE_USES_SSL_3                = 0x01000000;
+  const unsigned long STATE_USES_WEAK_CRYPTO          = 0x02000000;
+  const unsigned long STATE_CERT_USER_OVERRIDDEN      = 0x04000000;
+
+  /**
+   * Notification indicating the state has changed for one of the requests
+   * associated with aWebProgress.
+   *
+   * @param aWebProgress
+   *        The nsIWebProgress instance that fired the notification
+   * @param aRequest
+   *        The nsIRequest that has changed state.
+   * @param aStateFlags
+   *        Flags indicating the new state.  This value is a combination of one
+   *        of the State Transition Flags and one or more of the State Type
+   *        Flags defined above.  Any undefined bits are reserved for future
+   *        use.
+   * @param aStatus
+   *        Error status code associated with the state change.  This parameter
+   *        should be ignored unless aStateFlags includes the STATE_STOP bit.
+   *        The status code indicates success or failure of the request
+   *        associated with the state change.  NOTE: aStatus may be a success
+   *        code even for server generated errors, such as the HTTP 404 error.
+   *        In such cases, the request itself should be queried for extended
+   *        error information (e.g., for HTTP requests see nsIHttpChannel).
+   */
+  void onStateChange(in nsIWebProgress aWebProgress,
+                     in nsIRequest aRequest,
+                     in unsigned long aStateFlags,
+                     in nsresult aStatus);
+
+  /**
+   * Notification that the progress has changed for one of the requests
+   * associated with aWebProgress.  Progress totals are reset to zero when all
+   * requests in aWebProgress complete (corresponding to onStateChange being
+   * called with aStateFlags including the STATE_STOP and STATE_IS_WINDOW
+   * flags).
+   *
+   * @param aWebProgress
+   *        The nsIWebProgress instance that fired the notification.
+   * @param aRequest
+   *        The nsIRequest that has new progress.
+   * @param aCurSelfProgress
+   *        The current progress for aRequest.
+   * @param aMaxSelfProgress
+   *        The maximum progress for aRequest.
+   * @param aCurTotalProgress
+   *        The current progress for all requests associated with aWebProgress.
+   * @param aMaxTotalProgress
+   *        The total progress for all requests associated with aWebProgress.
+   *
+   * NOTE: If any progress value is unknown, or if its value would exceed the
+   * maximum value of type long, then its value is replaced with -1.
+   *
+   * NOTE: If the object also implements nsIWebProgressListener2 and the caller
+   * knows about that interface, this function will not be called. Instead,
+   * nsIWebProgressListener2::onProgressChange64 will be called.
+   */
+  void onProgressChange(in nsIWebProgress aWebProgress,
+                        in nsIRequest aRequest,
+                        in long aCurSelfProgress,
+                        in long aMaxSelfProgress,
+                        in long aCurTotalProgress,
+                        in long aMaxTotalProgress);
+
+  /**
+   * Flags for onLocationChange
+   *
+   * LOCATION_CHANGE_SAME_DOCUMENT
+   *   This flag is on when |aWebProgress| did not load a new document. 
+   *   For example, the location change is due to an anchor scroll or a
+   *   pushState/popState/replaceState.
+   *
+   * LOCATION_CHANGE_ERROR_PAGE
+   *   This flag is on when |aWebProgress| redirected from the requested
+   *   contents to an internal page to show error status, such as
+   *   <about:neterror>, <about:certerror> and so on.
+   *
+   *   Generally speaking, |aURI| and |aRequest| are the original data. DOM
+   *   |window.location.href| is also the original location, while
+   *   |document.documentURI| is the redirected location. Sometimes |aURI| is
+   *   <about:blank> and |aRequest| is null when the original data does not
+   +   remain.
+   *
+   *   |aWebProgress| does NOT set this flag when it did not try to load a new
+   *   document. In this case, it should set LOCATION_CHANGE_SAME_DOCUMENT.
+   */
+  const unsigned long LOCATION_CHANGE_SAME_DOCUMENT   = 0x00000001;
+  const unsigned long LOCATION_CHANGE_ERROR_PAGE      = 0x00000002;
+
+  /**
+   * Called when the location of the window being watched changes.  This is not
+   * when a load is requested, but rather once it is verified that the load is
+   * going to occur in the given window.  For instance, a load that starts in a
+   * window might send progress and status messages for the new site, but it
+   * will not send the onLocationChange until we are sure that we are loading
+   * this new page here.
+   *
+   * @param aWebProgress
+   *        The nsIWebProgress instance that fired the notification.
+   * @param aRequest
+   *        The associated nsIRequest.  This may be null in some cases.
+   * @param aLocation
+   *        The URI of the location that is being loaded.
+   * @param aFlags
+   *        This is a value which explains the situation or the reason why
+   *        the location has changed.
+   */
+  void onLocationChange(in nsIWebProgress aWebProgress,
+                        in nsIRequest aRequest,
+                        in nsIURI aLocation,
+                        [optional] in unsigned long aFlags);
+
+  /**
+   * Notification that the status of a request has changed.  The status message
+   * is intended to be displayed to the user (e.g., in the status bar of the
+   * browser).
+   *
+   * @param aWebProgress
+   *        The nsIWebProgress instance that fired the notification.
+   * @param aRequest
+   *        The nsIRequest that has new status.
+   * @param aStatus
+   *        This value is not an error code.  Instead, it is a numeric value
+   *        that indicates the current status of the request.  This interface
+   *        does not define the set of possible status codes.  NOTE: Some
+   *        status values are defined by nsITransport and nsISocketTransport.
+   * @param aMessage
+   *        Localized text corresponding to aStatus.
+   */
+  void onStatusChange(in nsIWebProgress aWebProgress,
+                      in nsIRequest aRequest,
+                      in nsresult aStatus,
+                      in wstring aMessage);
+
+  /**
+   * Notification called for security progress.  This method will be called on
+   * security transitions (eg HTTP -> HTTPS, HTTPS -> HTTP, FOO -> HTTPS) and
+   * after document load completion.  It might also be called if an error
+   * occurs during network loading.
+   *
+   * @param aWebProgress
+   *        The nsIWebProgress instance that fired the notification.
+   * @param aRequest
+   *        The nsIRequest that has new security state.
+   * @param aState
+   *        A value composed of the Security State Flags and the Security
+   *        Strength Flags listed above.  Any undefined bits are reserved for
+   *        future use.
+   *
+   * NOTE: These notifications will only occur if a security package is
+   * installed.
+   */
+  void onSecurityChange(in nsIWebProgress aWebProgress,
+                        in nsIRequest aRequest,
+                        in unsigned long aState);
+};
diff --git a/uriloader/base/nsIWebProgressListener2.idl b/uriloader/base/nsIWebProgressListener2.idl
new file mode 100644
index 000000000..87701f8d2
--- /dev/null
+++ b/uriloader/base/nsIWebProgressListener2.idl
@@ -0,0 +1,69 @@
+/* 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 "nsIWebProgressListener.idl"
+
+/**
+ * An extended version of nsIWebProgressListener.
+ */
+[scriptable, uuid(dde39de0-e4e0-11da-8ad9-0800200c9a66)]
+interface nsIWebProgressListener2 : nsIWebProgressListener {
+  /**
+   * Notification that the progress has changed for one of the requests
+   * associated with aWebProgress.  Progress totals are reset to zero when all
+   * requests in aWebProgress complete (corresponding to onStateChange being
+   * called with aStateFlags including the STATE_STOP and STATE_IS_WINDOW
+   * flags).
+   *
+   * This function is identical to nsIWebProgressListener::onProgressChange,
+   * except that this function supports 64-bit values.
+   *
+   * @param aWebProgress
+   *        The nsIWebProgress instance that fired the notification.
+   * @param aRequest
+   *        The nsIRequest that has new progress.
+   * @param aCurSelfProgress
+   *        The current progress for aRequest.
+   * @param aMaxSelfProgress
+   *        The maximum progress for aRequest.
+   * @param aCurTotalProgress
+   *        The current progress for all requests associated with aWebProgress.
+   * @param aMaxTotalProgress
+   *        The total progress for all requests associated with aWebProgress.
+   *
+   * NOTE: If any progress value is unknown, then its value is replaced with -1.
+   *
+   * @see nsIWebProgressListener2::onProgressChange64
+   */
+  void onProgressChange64(in nsIWebProgress aWebProgress,
+                          in nsIRequest aRequest,
+                          in long long aCurSelfProgress,
+                          in long long aMaxSelfProgress,
+                          in long long aCurTotalProgress,
+                          in long long aMaxTotalProgress);
+
+  /**
+   * Notification that a refresh or redirect has been requested in aWebProgress
+   * For example, via a <meta http-equiv="refresh"> or an HTTP Refresh: header
+   *
+   * @param aWebProgress
+   *        The nsIWebProgress instance that fired the notification.
+   * @param aRefreshURI
+   *        The new URI that aWebProgress has requested redirecting to.
+   * @param aMillis
+   *        The delay (in milliseconds) before refresh.
+   * @param aSameURI
+   *        True if aWebProgress is requesting a refresh of the
+   *        current URI.
+   *        False if aWebProgress is requesting a redirection to
+   *        a different URI.
+   *
+   * @return True if the refresh may proceed.
+   *         False if the refresh should be aborted.
+   */
+  boolean onRefreshAttempted(in nsIWebProgress aWebProgress,
+                             in nsIURI aRefreshURI,
+                             in long aMillis,
+                             in boolean aSameURI);
+};
diff --git a/uriloader/base/nsURILoader.cpp b/uriloader/base/nsURILoader.cpp
new file mode 100644
index 000000000..69475d68f
--- /dev/null
+++ b/uriloader/base/nsURILoader.cpp
@@ -0,0 +1,966 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode:nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sts=2 sw=2 et cin: */
+/* 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 "nsURILoader.h"
+#include "nsAutoPtr.h"
+#include "nsIURIContentListener.h"
+#include "nsIContentHandler.h"
+#include "nsILoadGroup.h"
+#include "nsIDocumentLoader.h"
+#include "nsIWebProgress.h"
+#include "nsIWebProgressListener.h"
+#include "nsIIOService.h"
+#include "nsIServiceManager.h"
+#include "nsIStreamListener.h"
+#include "nsIURI.h"
+#include "nsIChannel.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIProgressEventSink.h"
+#include "nsIInputStream.h"
+#include "nsIStreamConverterService.h"
+#include "nsWeakReference.h"
+#include "nsIHttpChannel.h"
+#include "nsIMultiPartChannel.h"
+#include "netCore.h"
+#include "nsCRT.h"
+#include "nsIDocShell.h"
+#include "nsIDocShellTreeItem.h"
+#include "nsIDocShellTreeOwner.h"
+#include "nsIThreadRetargetableStreamListener.h"
+
+#include "nsXPIDLString.h"
+#include "nsString.h"
+#include "nsThreadUtils.h"
+#include "nsReadableUtils.h"
+#include "nsError.h"
+
+#include "nsICategoryManager.h"
+#include "nsCExternalHandlerService.h" // contains contractids for the helper app service
+
+#include "nsIMIMEHeaderParam.h"
+#include "nsNetCID.h"
+
+#include "nsMimeTypes.h"
+
+#include "nsDocLoader.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Preferences.h"
+#include "nsContentUtils.h"
+
+mozilla::LazyLogModule nsURILoader::mLog("URILoader");
+
+#define LOG(args) MOZ_LOG(nsURILoader::mLog, mozilla::LogLevel::Debug, args)
+#define LOG_ERROR(args) MOZ_LOG(nsURILoader::mLog, mozilla::LogLevel::Error, args)
+#define LOG_ENABLED() MOZ_LOG_TEST(nsURILoader::mLog, mozilla::LogLevel::Debug)
+
+#define NS_PREF_DISABLE_BACKGROUND_HANDLING \
+    "security.exthelperapp.disable_background_handling"
+
+/**
+ * The nsDocumentOpenInfo contains the state required when a single
+ * document is being opened in order to discover the content type...
+ * Each instance remains alive until its target URL has been loaded
+ * (or aborted).
+ */
+class nsDocumentOpenInfo final : public nsIStreamListener
+                               , public nsIThreadRetargetableStreamListener
+{
+public:
+  // Needed for nsCOMPtr to work right... Don't call this!
+  nsDocumentOpenInfo();
+
+  // Real constructor
+  // aFlags is a combination of the flags on nsIURILoader
+  nsDocumentOpenInfo(nsIInterfaceRequestor* aWindowContext,
+                     uint32_t aFlags,
+                     nsURILoader* aURILoader);
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  /**
+   * Prepares this object for receiving data. The stream
+   * listener methods of this class must not be called before calling this
+   * method.
+   */
+  nsresult Prepare();
+
+  // Call this (from OnStartRequest) to attempt to find an nsIStreamListener to
+  // take the data off our hands.
+  nsresult DispatchContent(nsIRequest *request, nsISupports * aCtxt);
+
+  // Call this if we need to insert a stream converter from aSrcContentType to
+  // aOutContentType into the StreamListener chain.  DO NOT call it if the two
+  // types are the same, since no conversion is needed in that case.
+  nsresult ConvertData(nsIRequest *request,
+                       nsIURIContentListener *aListener,
+                       const nsACString & aSrcContentType,
+                       const nsACString & aOutContentType);
+
+  /**
+   * Function to attempt to use aListener to handle the load.  If
+   * true is returned, nothing else needs to be done; if false
+   * is returned, then a different way of handling the load should be
+   * tried.
+   */
+  bool TryContentListener(nsIURIContentListener* aListener,
+                            nsIChannel* aChannel);
+
+  // nsIRequestObserver methods:
+  NS_DECL_NSIREQUESTOBSERVER
+
+  // nsIStreamListener methods:
+  NS_DECL_NSISTREAMLISTENER
+
+  // nsIThreadRetargetableStreamListener
+  NS_DECL_NSITHREADRETARGETABLESTREAMLISTENER
+protected:
+  ~nsDocumentOpenInfo();
+
+protected:
+  /**
+   * The first content listener to try dispatching data to.  Typically
+   * the listener associated with the entity that originated the load.
+   */
+  nsCOMPtr<nsIURIContentListener> m_contentListener;
+
+  /**
+   * The stream listener to forward nsIStreamListener notifications
+   * to.  This is set once the load is dispatched.
+   */
+  nsCOMPtr<nsIStreamListener> m_targetStreamListener;
+
+  /**
+   * A pointer to the entity that originated the load. We depend on getting
+   * things like nsIURIContentListeners, nsIDOMWindows, etc off of it.
+   */
+  nsCOMPtr<nsIInterfaceRequestor> m_originalContext;
+
+  /**
+   * IS_CONTENT_PREFERRED is used for the boolean to pass to CanHandleContent
+   * (also determines whether we use CanHandleContent or IsPreferred).
+   * DONT_RETARGET means that we will only try m_originalContext, no other
+   * listeners.
+   */
+  uint32_t mFlags;
+
+  /**
+   * The type of the data we will be trying to dispatch.
+   */
+  nsCString mContentType;
+
+  /**
+   * Reference to the URILoader service so we can access its list of
+   * nsIURIContentListeners.
+   */
+  RefPtr<nsURILoader> mURILoader;
+};
+
+NS_IMPL_ADDREF(nsDocumentOpenInfo)
+NS_IMPL_RELEASE(nsDocumentOpenInfo)
+
+NS_INTERFACE_MAP_BEGIN(nsDocumentOpenInfo)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIRequestObserver)
+  NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
+  NS_INTERFACE_MAP_ENTRY(nsIStreamListener)
+  NS_INTERFACE_MAP_ENTRY(nsIThreadRetargetableStreamListener)
+NS_INTERFACE_MAP_END_THREADSAFE
+
+nsDocumentOpenInfo::nsDocumentOpenInfo()
+{
+  NS_NOTREACHED("This should never be called\n");
+}
+
+nsDocumentOpenInfo::nsDocumentOpenInfo(nsIInterfaceRequestor* aWindowContext,
+                                       uint32_t aFlags,
+                                       nsURILoader* aURILoader)
+  : m_originalContext(aWindowContext),
+    mFlags(aFlags),
+    mURILoader(aURILoader)
+{
+}
+
+nsDocumentOpenInfo::~nsDocumentOpenInfo()
+{
+}
+
+nsresult nsDocumentOpenInfo::Prepare()
+{
+  LOG(("[0x%p] nsDocumentOpenInfo::Prepare", this));
+
+  nsresult rv;
+
+  // ask our window context if it has a uri content listener...
+  m_contentListener = do_GetInterface(m_originalContext, &rv);
+  return rv;
+}
+
+NS_IMETHODIMP nsDocumentOpenInfo::OnStartRequest(nsIRequest *request, nsISupports * aCtxt)
+{
+  LOG(("[0x%p] nsDocumentOpenInfo::OnStartRequest", this));
+  MOZ_ASSERT(request);
+  if (!request) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsresult rv = NS_OK;
+
+  //
+  // Deal with "special" HTTP responses:
+  // 
+  // - In the case of a 204 (No Content) or 205 (Reset Content) response, do
+  //   not try to find a content handler.  Return NS_BINDING_ABORTED to cancel
+  //   the request.  This has the effect of ensuring that the DocLoader does
+  //   not try to interpret this as a real request.
+  // 
+  nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(request, &rv));
+
+  if (NS_SUCCEEDED(rv)) {
+    uint32_t responseCode = 0;
+
+    rv = httpChannel->GetResponseStatus(&responseCode);
+
+    if (NS_FAILED(rv)) {
+      LOG_ERROR(("  Failed to get HTTP response status"));
+      
+      // behave as in the canceled case
+      return NS_OK;
+    }
+
+    LOG(("  HTTP response status: %d", responseCode));
+
+    if (204 == responseCode || 205 == responseCode) {
+      return NS_BINDING_ABORTED;
+    }
+
+    static bool sLargeAllocationHeaderEnabled = false;
+    static bool sCachedLargeAllocationPref = false;
+    if (!sCachedLargeAllocationPref) {
+      sCachedLargeAllocationPref = true;
+      mozilla::Preferences::AddBoolVarCache(&sLargeAllocationHeaderEnabled,
+                                            "dom.largeAllocationHeader.enabled");
+    }
+
+    if (sLargeAllocationHeaderEnabled) {
+      // If we have a Large-Allocation header, let's check if we should perform a process switch.
+      nsAutoCString largeAllocationHeader;
+      rv = httpChannel->GetResponseHeader(NS_LITERAL_CSTRING("Large-Allocation"), largeAllocationHeader);
+      if (NS_SUCCEEDED(rv) && nsContentUtils::AttemptLargeAllocationLoad(httpChannel)) {
+        return NS_BINDING_ABORTED;
+      }
+    }
+  }
+
+  //
+  // Make sure that the transaction has succeeded, so far...
+  //
+  nsresult status;
+
+  rv = request->GetStatus(&status);
+  
+  NS_ASSERTION(NS_SUCCEEDED(rv), "Unable to get request status!");
+  if (NS_FAILED(rv)) return rv;
+
+  if (NS_FAILED(status)) {
+    LOG_ERROR(("  Request failed, status: 0x%08X", rv));
+  
+    //
+    // The transaction has already reported an error - so it will be torn
+    // down. Therefore, it is not necessary to return an error code...
+    //
+    return NS_OK;
+  }
+
+  rv = DispatchContent(request, aCtxt);
+
+  LOG(("  After dispatch, m_targetStreamListener: 0x%p, rv: 0x%08X", m_targetStreamListener.get(), rv));
+
+  NS_ASSERTION(NS_SUCCEEDED(rv) || !m_targetStreamListener,
+               "Must not have an m_targetStreamListener with a failure return!");
+
+  NS_ENSURE_SUCCESS(rv, rv);
+  
+  if (m_targetStreamListener)
+    rv = m_targetStreamListener->OnStartRequest(request, aCtxt);
+
+  LOG(("  OnStartRequest returning: 0x%08X", rv));
+  
+  return rv;
+}
+
+NS_IMETHODIMP
+nsDocumentOpenInfo::CheckListenerChain()
+{
+  NS_ASSERTION(NS_IsMainThread(), "Should be on the main thread!");
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIThreadRetargetableStreamListener> retargetableListener =
+    do_QueryInterface(m_targetStreamListener, &rv);
+  if (retargetableListener) {
+    rv = retargetableListener->CheckListenerChain();
+  }
+  LOG(("[0x%p] nsDocumentOpenInfo::CheckListenerChain %s listener %p rv %x",
+       this, (NS_SUCCEEDED(rv) ? "success" : "failure"),
+       (nsIStreamListener*)m_targetStreamListener, rv));
+  return rv;
+}
+
+NS_IMETHODIMP
+nsDocumentOpenInfo::OnDataAvailable(nsIRequest *request, nsISupports * aCtxt,
+                                    nsIInputStream * inStr,
+                                    uint64_t sourceOffset, uint32_t count)
+{
+  // if we have retarged to the end stream listener, then forward the call....
+  // otherwise, don't do anything
+
+  nsresult rv = NS_OK;
+  
+  if (m_targetStreamListener)
+    rv = m_targetStreamListener->OnDataAvailable(request, aCtxt, inStr, sourceOffset, count);
+  return rv;
+}
+
+NS_IMETHODIMP nsDocumentOpenInfo::OnStopRequest(nsIRequest *request, nsISupports *aCtxt, 
+                                                nsresult aStatus)
+{
+  LOG(("[0x%p] nsDocumentOpenInfo::OnStopRequest", this));
+  
+  if ( m_targetStreamListener)
+  {
+    nsCOMPtr<nsIStreamListener> listener(m_targetStreamListener);
+
+    // If this is a multipart stream, we could get another
+    // OnStartRequest after this... reset state.
+    m_targetStreamListener = nullptr;
+    mContentType.Truncate();
+    listener->OnStopRequest(request, aCtxt, aStatus);
+  }
+
+  // Remember...
+  // In the case of multiplexed streams (such as multipart/x-mixed-replace)
+  // these stream listener methods could be called again :-)
+  //
+  return NS_OK;
+}
+
+nsresult nsDocumentOpenInfo::DispatchContent(nsIRequest *request, nsISupports * aCtxt)
+{
+  LOG(("[0x%p] nsDocumentOpenInfo::DispatchContent for type '%s'", this, mContentType.get()));
+
+  NS_PRECONDITION(!m_targetStreamListener,
+                  "Why do we already have a target stream listener?");
+  
+  nsresult rv;
+  nsCOMPtr<nsIChannel> aChannel = do_QueryInterface(request);
+  if (!aChannel) {
+    LOG_ERROR(("  Request is not a channel.  Bailing."));
+    return NS_ERROR_FAILURE;
+  }
+
+  NS_NAMED_LITERAL_CSTRING(anyType, "*/*");
+  if (mContentType.IsEmpty() || mContentType == anyType) {
+    rv = aChannel->GetContentType(mContentType);
+    if (NS_FAILED(rv)) return rv;
+    LOG(("  Got type from channel: '%s'", mContentType.get()));
+  }
+
+  bool isGuessFromExt =
+    mContentType.LowerCaseEqualsASCII(APPLICATION_GUESS_FROM_EXT);
+  if (isGuessFromExt) {
+    // Reset to application/octet-stream for now; no one other than the
+    // external helper app service should see APPLICATION_GUESS_FROM_EXT.
+    mContentType = APPLICATION_OCTET_STREAM;
+    aChannel->SetContentType(NS_LITERAL_CSTRING(APPLICATION_OCTET_STREAM));
+  }
+
+  // Check whether the data should be forced to be handled externally.  This
+  // could happen because the Content-Disposition header is set so, or, in the
+  // future, because the user has specified external handling for the MIME
+  // type.
+  bool forceExternalHandling = false;
+  uint32_t disposition;
+  rv = aChannel->GetContentDisposition(&disposition);
+
+  bool allowContentDispositionToForceExternalHandling = true;
+
+#ifdef MOZ_B2G
+
+  // On B2G, OMA content files should never be handled by an external handler
+  // (even if the server specifies Content-Disposition: attachment) because the
+  // data should never be stored on an unencrypted form.
+  allowContentDispositionToForceExternalHandling =
+    !mContentType.LowerCaseEqualsASCII("application/vnd.oma.drm.message");
+
+#endif
+
+  if (NS_SUCCEEDED(rv) && (disposition == nsIChannel::DISPOSITION_ATTACHMENT) &&
+      allowContentDispositionToForceExternalHandling) {
+    forceExternalHandling = true;
+  }
+
+  LOG(("  forceExternalHandling: %s", forceExternalHandling ? "yes" : "no"));
+
+  // The type or data the contentListener wants.
+  nsXPIDLCString desiredContentType;
+
+  if (!forceExternalHandling)
+  {
+    //
+    // First step: See whether m_contentListener wants to handle this
+    // content type.
+    //
+    if (m_contentListener && TryContentListener(m_contentListener, aChannel)) {
+      LOG(("  Success!  Our default listener likes this type"));
+      // All done here
+      return NS_OK;
+    }
+
+    // If we aren't allowed to try other listeners, just skip through to
+    // trying to convert the data.
+    if (!(mFlags & nsIURILoader::DONT_RETARGET)) {
+
+      //
+      // Second step: See whether some other registered listener wants
+      // to handle this content type.
+      //
+      int32_t count = mURILoader->m_listeners.Count();
+      nsCOMPtr<nsIURIContentListener> listener;
+      for (int32_t i = 0; i < count; i++) {
+        listener = do_QueryReferent(mURILoader->m_listeners[i]);
+        if (listener) {
+          if (TryContentListener(listener, aChannel)) {
+            LOG(("  Found listener registered on the URILoader"));
+            return NS_OK;
+          }
+        } else {
+          // remove from the listener list, reset i and update count
+          mURILoader->m_listeners.RemoveObjectAt(i--);
+          --count;
+        }
+      }
+
+      //
+      // Third step: Try to find a content listener that has not yet had
+      // the chance to register, as it is contained in a not-yet-loaded
+      // module, but which has registered a contract ID.
+      //
+      nsCOMPtr<nsICategoryManager> catman =
+        do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
+      if (catman) {
+        nsXPIDLCString contractidString;
+        rv = catman->GetCategoryEntry(NS_CONTENT_LISTENER_CATEGORYMANAGER_ENTRY,
+                                      mContentType.get(),
+                                      getter_Copies(contractidString));
+        if (NS_SUCCEEDED(rv) && !contractidString.IsEmpty()) {
+          LOG(("  Listener contractid for '%s' is '%s'",
+               mContentType.get(), contractidString.get()));
+
+          listener = do_CreateInstance(contractidString);
+          LOG(("  Listener from category manager: 0x%p", listener.get()));
+          
+          if (listener && TryContentListener(listener, aChannel)) {
+            LOG(("  Listener from category manager likes this type"));
+            return NS_OK;
+          }
+        }
+      }
+
+      //
+      // Fourth step: try to find an nsIContentHandler for our type.
+      //
+      nsAutoCString handlerContractID (NS_CONTENT_HANDLER_CONTRACTID_PREFIX);
+      handlerContractID += mContentType;
+
+      nsCOMPtr<nsIContentHandler> contentHandler =
+        do_CreateInstance(handlerContractID.get());
+      if (contentHandler) {
+        LOG(("  Content handler found"));
+        rv = contentHandler->HandleContent(mContentType.get(),
+                                           m_originalContext, request);
+        // XXXbz returning an error code to represent handling the
+        // content is just bizarre!
+        if (rv != NS_ERROR_WONT_HANDLE_CONTENT) {
+          if (NS_FAILED(rv)) {
+            // The content handler has unexpectedly failed.  Cancel the request
+            // just in case the handler didn't...
+            LOG(("  Content handler failed.  Aborting load"));
+            request->Cancel(rv);
+          }
+          else {
+            LOG(("  Content handler taking over load"));
+          }
+
+          return rv;
+        }
+      }
+    } else {
+      LOG(("  DONT_RETARGET flag set, so skipped over random other content "
+           "listeners and content handlers"));
+    }
+
+    //
+    // Fifth step:  If no listener prefers this type, see if any stream
+    //              converters exist to transform this content type into
+    //              some other.
+    //
+    // Don't do this if the server sent us a MIME type of "*/*" because they saw
+    // it in our Accept header and got confused.
+    // XXXbz have to be careful here; may end up in some sort of bizarre infinite
+    // decoding loop.
+    if (mContentType != anyType) {
+      rv = ConvertData(request, m_contentListener, mContentType, anyType);
+      if (NS_FAILED(rv)) {
+        m_targetStreamListener = nullptr;
+      } else if (m_targetStreamListener) {
+        // We found a converter for this MIME type.  We'll just pump data into it
+        // and let the downstream nsDocumentOpenInfo handle things.
+        LOG(("  Converter taking over now"));
+        return NS_OK;
+      }
+    }
+  }
+
+  NS_ASSERTION(!m_targetStreamListener,
+               "If we found a listener, why are we not using it?");
+  
+  if (mFlags & nsIURILoader::DONT_RETARGET) {
+    LOG(("  External handling forced or (listener not interested and no "
+         "stream converter exists), and retargeting disallowed -> aborting"));
+    return NS_ERROR_WONT_HANDLE_CONTENT;
+  }
+
+  // Before dispatching to the external helper app service, check for an HTTP
+  // error page.  If we got one, we don't want to handle it with a helper app,
+  // really.
+  nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(request));
+  if (httpChannel) {
+    bool requestSucceeded;
+    httpChannel->GetRequestSucceeded(&requestSucceeded);
+    if (!requestSucceeded) {
+      // returning error from OnStartRequest will cancel the channel
+      return NS_ERROR_FILE_NOT_FOUND;
+    }
+  }
+  
+  // Sixth step:
+  //
+  // All attempts to dispatch this content have failed.  Just pass it off to
+  // the helper app service.
+  //
+
+  //
+  // Optionally, we may want to disable background handling by the external
+  // helper application service.
+  //
+  if (mozilla::Preferences::GetBool(NS_PREF_DISABLE_BACKGROUND_HANDLING,
+                                    false)) {
+    // First, we will ensure that the parent docshell is in an active
+    // state as we will disallow all external application handling unless it is
+    // in the foreground.
+    nsCOMPtr<nsIDocShell> docShell(do_GetInterface(m_originalContext));
+    if (!docShell) {
+      // If we can't perform our security check we definitely don't want to go
+      // any further!
+      LOG(("Failed to get DocShell to ensure it is active before anding off to "
+           "helper app service. Aborting."));
+      return NS_ERROR_FAILURE;
+    }
+
+    // Ensure the DocShell is active before continuing.
+    bool isActive = false;
+    docShell->GetIsActive(&isActive);
+    if (!isActive) {
+      LOG(("  Check for active DocShell returned false. Aborting hand off to "
+           "helper app service."));
+      return NS_ERROR_DOM_SECURITY_ERR;
+    }
+  }
+
+  nsCOMPtr<nsIExternalHelperAppService> helperAppService =
+    do_GetService(NS_EXTERNALHELPERAPPSERVICE_CONTRACTID, &rv);
+  if (helperAppService) {
+    LOG(("  Passing load off to helper app service"));
+
+    // Set these flags to indicate that the channel has been targeted and that
+    // we are not using the original consumer.
+    nsLoadFlags loadFlags = 0;
+    request->GetLoadFlags(&loadFlags);
+    request->SetLoadFlags(loadFlags | nsIChannel::LOAD_RETARGETED_DOCUMENT_URI
+                                    | nsIChannel::LOAD_TARGETED);
+
+    if (isGuessFromExt) {
+      mContentType = APPLICATION_GUESS_FROM_EXT;
+      aChannel->SetContentType(NS_LITERAL_CSTRING(APPLICATION_GUESS_FROM_EXT));
+    }
+
+    rv = helperAppService->DoContent(mContentType,
+                                     request,
+                                     m_originalContext,
+                                     false,
+                                     nullptr,
+                                     getter_AddRefs(m_targetStreamListener));
+    if (NS_FAILED(rv)) {
+      request->SetLoadFlags(loadFlags);
+      m_targetStreamListener = nullptr;
+    }
+  }
+      
+  NS_ASSERTION(m_targetStreamListener || NS_FAILED(rv),
+               "There is no way we should be successful at this point without a m_targetStreamListener");
+  return rv;
+}
+
+nsresult
+nsDocumentOpenInfo::ConvertData(nsIRequest *request,
+                                nsIURIContentListener* aListener,
+                                const nsACString& aSrcContentType,
+                                const nsACString& aOutContentType)
+{
+  LOG(("[0x%p] nsDocumentOpenInfo::ConvertData from '%s' to '%s'", this,
+       PromiseFlatCString(aSrcContentType).get(),
+       PromiseFlatCString(aOutContentType).get()));
+
+  NS_PRECONDITION(aSrcContentType != aOutContentType,
+                  "ConvertData called when the two types are the same!");
+  nsresult rv = NS_OK;
+
+  nsCOMPtr<nsIStreamConverterService> StreamConvService = 
+    do_GetService(NS_STREAMCONVERTERSERVICE_CONTRACTID, &rv);
+  if (NS_FAILED(rv)) return rv;
+
+  LOG(("  Got converter service"));
+  
+  // When applying stream decoders, it is necessary to "insert" an 
+  // intermediate nsDocumentOpenInfo instance to handle the targeting of
+  // the "final" stream or streams.
+  //
+  // For certain content types (ie. multi-part/x-mixed-replace) the input
+  // stream is split up into multiple destination streams.  This
+  // intermediate instance is used to target these "decoded" streams...
+  //
+  RefPtr<nsDocumentOpenInfo> nextLink =
+    new nsDocumentOpenInfo(m_originalContext, mFlags, mURILoader);
+
+  LOG(("  Downstream DocumentOpenInfo would be: 0x%p", nextLink.get()));
+  
+  // Make sure nextLink starts with the contentListener that said it wanted the
+  // results of this decode.
+  nextLink->m_contentListener = aListener;
+  // Also make sure it has to look for a stream listener to pump data into.
+  nextLink->m_targetStreamListener = nullptr;
+
+  // Make sure that nextLink treats the data as aOutContentType when
+  // dispatching; that way even if the stream converters don't change the type
+  // on the channel we will still do the right thing.  If aOutContentType is
+  // */*, that's OK -- that will just indicate to nextLink that it should get
+  // the type off the channel.
+  nextLink->mContentType = aOutContentType;
+
+  // The following call sets m_targetStreamListener to the input end of the
+  // stream converter and sets the output end of the stream converter to
+  // nextLink.  As we pump data into m_targetStreamListener the stream
+  // converter will convert it and pass the converted data to nextLink.
+  return StreamConvService->AsyncConvertData(PromiseFlatCString(aSrcContentType).get(), 
+                                             PromiseFlatCString(aOutContentType).get(), 
+                                             nextLink, 
+                                             request,
+                                             getter_AddRefs(m_targetStreamListener));
+}
+
+bool
+nsDocumentOpenInfo::TryContentListener(nsIURIContentListener* aListener,
+                                       nsIChannel* aChannel)
+{
+  LOG(("[0x%p] nsDocumentOpenInfo::TryContentListener; mFlags = 0x%x",
+       this, mFlags));
+
+  NS_PRECONDITION(aListener, "Must have a non-null listener");
+  NS_PRECONDITION(aChannel, "Must have a channel");
+  
+  bool listenerWantsContent = false;
+  nsXPIDLCString typeToUse;
+  
+  if (mFlags & nsIURILoader::IS_CONTENT_PREFERRED) {
+    aListener->IsPreferred(mContentType.get(),
+                           getter_Copies(typeToUse),
+                           &listenerWantsContent);
+  } else {
+    aListener->CanHandleContent(mContentType.get(), false,
+                                getter_Copies(typeToUse),
+                                &listenerWantsContent);
+  }
+  if (!listenerWantsContent) {
+    LOG(("  Listener is not interested"));
+    return false;
+  }
+
+  if (!typeToUse.IsEmpty() && typeToUse != mContentType) {
+    // Need to do a conversion here.
+
+    nsresult rv = ConvertData(aChannel, aListener, mContentType, typeToUse);
+
+    if (NS_FAILED(rv)) {
+      // No conversion path -- we don't want this listener, if we got one
+      m_targetStreamListener = nullptr;
+    }
+
+    LOG(("  Found conversion: %s", m_targetStreamListener ? "yes" : "no"));
+    
+    // m_targetStreamListener is now the input end of the converter, and we can
+    // just pump the data in there, if it exists.  If it does not, we need to
+    // try other nsIURIContentListeners.
+    return m_targetStreamListener != nullptr;
+  }
+
+  // At this point, aListener wants data of type mContentType.  Let 'em have
+  // it.  But first, if we are retargeting, set an appropriate flag on the
+  // channel
+  nsLoadFlags loadFlags = 0;
+  aChannel->GetLoadFlags(&loadFlags);
+
+  // Set this flag to indicate that the channel has been targeted at a final
+  // consumer.  This load flag is tested in nsDocLoader::OnProgress.
+  nsLoadFlags newLoadFlags = nsIChannel::LOAD_TARGETED;
+
+  nsCOMPtr<nsIURIContentListener> originalListener =
+    do_GetInterface(m_originalContext);
+  if (originalListener != aListener) {
+    newLoadFlags |= nsIChannel::LOAD_RETARGETED_DOCUMENT_URI;
+  }
+  aChannel->SetLoadFlags(loadFlags | newLoadFlags);
+  
+  bool abort = false;
+  bool isPreferred = (mFlags & nsIURILoader::IS_CONTENT_PREFERRED) != 0;
+  nsresult rv = aListener->DoContent(mContentType,
+                                     isPreferred,
+                                     aChannel,
+                                     getter_AddRefs(m_targetStreamListener),
+                                     &abort);
+    
+  if (NS_FAILED(rv)) {
+    LOG_ERROR(("  DoContent failed"));
+    
+    // Unset the RETARGETED_DOCUMENT_URI flag if we set it...
+    aChannel->SetLoadFlags(loadFlags);
+    m_targetStreamListener = nullptr;
+    return false;
+  }
+
+  if (abort) {
+    // Nothing else to do here -- aListener is handling it all.  Make
+    // sure m_targetStreamListener is null so we don't do anything
+    // after this point.
+    LOG(("  Listener has aborted the load"));
+    m_targetStreamListener = nullptr;
+  }
+
+  NS_ASSERTION(abort || m_targetStreamListener, "DoContent returned no listener?");
+
+  // aListener is handling the load from this point on.  
+  return true;
+}
+
+
+///////////////////////////////////////////////////////////////////////////////////////////////
+// Implementation of nsURILoader
+///////////////////////////////////////////////////////////////////////////////////////////////
+
+nsURILoader::nsURILoader()
+{
+}
+
+nsURILoader::~nsURILoader()
+{
+}
+
+NS_IMPL_ADDREF(nsURILoader)
+NS_IMPL_RELEASE(nsURILoader)
+
+NS_INTERFACE_MAP_BEGIN(nsURILoader)
+   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIURILoader)
+   NS_INTERFACE_MAP_ENTRY(nsIURILoader)
+NS_INTERFACE_MAP_END
+
+NS_IMETHODIMP nsURILoader::RegisterContentListener(nsIURIContentListener * aContentListener)
+{
+  nsresult rv = NS_OK;
+
+  nsWeakPtr weakListener = do_GetWeakReference(aContentListener);
+  NS_ASSERTION(weakListener, "your URIContentListener must support weak refs!\n");
+  
+  if (weakListener)
+    m_listeners.AppendObject(weakListener);
+
+  return rv;
+} 
+
+NS_IMETHODIMP nsURILoader::UnRegisterContentListener(nsIURIContentListener * aContentListener)
+{
+  nsWeakPtr weakListener = do_GetWeakReference(aContentListener);
+  if (weakListener)
+    m_listeners.RemoveObject(weakListener);
+
+  return NS_OK;
+  
+}
+
+NS_IMETHODIMP nsURILoader::OpenURI(nsIChannel *channel, 
+                                   uint32_t aFlags,
+                                   nsIInterfaceRequestor *aWindowContext)
+{
+  NS_ENSURE_ARG_POINTER(channel);
+
+  if (LOG_ENABLED()) {
+    nsCOMPtr<nsIURI> uri;
+    channel->GetURI(getter_AddRefs(uri));
+    nsAutoCString spec;
+    uri->GetAsciiSpec(spec);
+    LOG(("nsURILoader::OpenURI for %s", spec.get()));
+  }
+
+  nsCOMPtr<nsIStreamListener> loader;
+  nsresult rv = OpenChannel(channel,
+                            aFlags,
+                            aWindowContext,
+                            false,
+                            getter_AddRefs(loader));
+
+  if (NS_SUCCEEDED(rv)) {
+    // this method is not complete!!! Eventually, we should first go
+    // to the content listener and ask them for a protocol handler...
+    // if they don't give us one, we need to go to the registry and get
+    // the preferred protocol handler. 
+
+    // But for now, I'm going to let necko do the work for us....
+    rv = channel->AsyncOpen(loader, nullptr);
+
+    // no content from this load - that's OK.
+    if (rv == NS_ERROR_NO_CONTENT) {
+      LOG(("  rv is NS_ERROR_NO_CONTENT -- doing nothing"));
+      rv = NS_OK;
+    }
+  } else if (rv == NS_ERROR_WONT_HANDLE_CONTENT) {
+    // Not really an error, from this method's point of view
+    rv = NS_OK;
+  }
+  return rv;
+}
+
+nsresult nsURILoader::OpenChannel(nsIChannel* channel,
+                                  uint32_t aFlags,
+                                  nsIInterfaceRequestor* aWindowContext,
+                                  bool aChannelIsOpen,
+                                  nsIStreamListener** aListener)
+{
+  NS_ASSERTION(channel, "Trying to open a null channel!");
+  NS_ASSERTION(aWindowContext, "Window context must not be null");
+
+  if (LOG_ENABLED()) {
+    nsCOMPtr<nsIURI> uri;
+    channel->GetURI(getter_AddRefs(uri));
+    nsAutoCString spec;
+    uri->GetAsciiSpec(spec);
+    LOG(("nsURILoader::OpenChannel for %s", spec.get()));
+  }
+
+  // Let the window context's uriListener know that the open is starting.  This
+  // gives that window a chance to abort the load process.
+  nsCOMPtr<nsIURIContentListener> winContextListener(do_GetInterface(aWindowContext));
+  if (winContextListener) {
+    nsCOMPtr<nsIURI> uri;
+    channel->GetURI(getter_AddRefs(uri));
+    if (uri) {
+      bool doAbort = false;
+      winContextListener->OnStartURIOpen(uri, &doAbort);
+
+      if (doAbort) {
+        LOG(("  OnStartURIOpen aborted load"));
+        return NS_ERROR_WONT_HANDLE_CONTENT;
+      }
+    }
+  }
+
+  // we need to create a DocumentOpenInfo object which will go ahead and open
+  // the url and discover the content type....
+  RefPtr<nsDocumentOpenInfo> loader =
+    new nsDocumentOpenInfo(aWindowContext, aFlags, this);
+
+  // Set the correct loadgroup on the channel
+  nsCOMPtr<nsILoadGroup> loadGroup(do_GetInterface(aWindowContext));
+
+  if (!loadGroup) {
+    // XXXbz This context is violating what we'd like to be the new uriloader
+    // api.... Set up a nsDocLoader to handle the loadgroup for this context.
+    // This really needs to go away!
+    nsCOMPtr<nsIURIContentListener> listener(do_GetInterface(aWindowContext));
+    if (listener) {
+      nsCOMPtr<nsISupports> cookie;
+      listener->GetLoadCookie(getter_AddRefs(cookie));
+      if (!cookie) {
+        RefPtr<nsDocLoader> newDocLoader = new nsDocLoader();
+        nsresult rv = newDocLoader->Init();
+        if (NS_FAILED(rv))
+          return rv;
+        rv = nsDocLoader::AddDocLoaderAsChildOfRoot(newDocLoader);
+        if (NS_FAILED(rv))
+          return rv;
+        cookie = nsDocLoader::GetAsSupports(newDocLoader);
+        listener->SetLoadCookie(cookie);
+      }
+      loadGroup = do_GetInterface(cookie);
+    }
+  }
+
+  // If the channel is pending, then we need to remove it from its current
+  // loadgroup
+  nsCOMPtr<nsILoadGroup> oldGroup;
+  channel->GetLoadGroup(getter_AddRefs(oldGroup));
+  if (aChannelIsOpen && !SameCOMIdentity(oldGroup, loadGroup)) {
+    // It is important to add the channel to the new group before
+    // removing it from the old one, so that the load isn't considered
+    // done as soon as the request is removed.
+    loadGroup->AddRequest(channel, nullptr);
+
+   if (oldGroup) {
+      oldGroup->RemoveRequest(channel, nullptr, NS_BINDING_RETARGETED);
+    }
+  }
+
+  channel->SetLoadGroup(loadGroup);
+
+  // prepare the loader for receiving data
+  nsresult rv = loader->Prepare();
+  if (NS_SUCCEEDED(rv))
+    NS_ADDREF(*aListener = loader);
+  return rv;
+}
+
+NS_IMETHODIMP nsURILoader::OpenChannel(nsIChannel* channel,
+                                       uint32_t aFlags,
+                                       nsIInterfaceRequestor* aWindowContext,
+                                       nsIStreamListener** aListener)
+{
+  bool pending;
+  if (NS_FAILED(channel->IsPending(&pending))) {
+    pending = false;
+  }
+
+  return OpenChannel(channel, aFlags, aWindowContext, pending, aListener);
+}
+
+NS_IMETHODIMP nsURILoader::Stop(nsISupports* aLoadCookie)
+{
+  nsresult rv;
+  nsCOMPtr<nsIDocumentLoader> docLoader;
+
+  NS_ENSURE_ARG_POINTER(aLoadCookie);
+
+  docLoader = do_GetInterface(aLoadCookie, &rv);
+  if (docLoader) {
+    rv = docLoader->Stop();
+  }
+  return rv;
+}
+
diff --git a/uriloader/base/nsURILoader.h b/uriloader/base/nsURILoader.h
new file mode 100644
index 000000000..2c5648dba
--- /dev/null
+++ b/uriloader/base/nsURILoader.h
@@ -0,0 +1,59 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsURILoader_h__
+#define nsURILoader_h__
+
+#include "nsCURILoader.h"
+#include "nsISupportsUtils.h"
+#include "nsCOMArray.h"
+#include "nsCOMPtr.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsString.h"
+#include "nsIWeakReference.h"
+#include "mozilla/Attributes.h"
+
+#include "mozilla/Logging.h"
+
+class nsDocumentOpenInfo;
+
+class nsURILoader final : public nsIURILoader
+{
+public:
+  NS_DECL_NSIURILOADER
+  NS_DECL_ISUPPORTS
+
+  nsURILoader();
+
+protected:
+  ~nsURILoader();
+
+  /**
+   * Equivalent to nsIURILoader::openChannel, but allows specifying whether the
+   * channel is opened already.
+   */
+  MOZ_MUST_USE nsresult OpenChannel(nsIChannel* channel,
+                                    uint32_t aFlags,
+                                    nsIInterfaceRequestor* aWindowContext,
+                                    bool aChannelOpen,
+                                    nsIStreamListener** aListener);
+
+  /**
+   * we shouldn't need to have an owning ref count on registered
+   * content listeners because they are supposed to unregister themselves
+   * when they go away. This array stores weak references
+   */
+  nsCOMArray<nsIWeakReference> m_listeners;
+
+  /**
+   * Logging.  The module is called "URILoader"
+   */
+  static mozilla::LazyLogModule mLog;
+  
+  friend class nsDocumentOpenInfo;
+};
+
+#endif /* nsURILoader_h__ */