Bug 1141337 - Update nsIWebBrowserPersistable to allow subframe targeting for Save Frame As. r=jld

This alters nsIWebBrowserPersistable so that startPersistence takes an
outerWindowID. This allows us to target a particular subframe from
beneath an nsFrameLoader, which is useful when attempting to Save
Frame As a remote browser.

browser/base/content/nsContextMenu.js

@@ -1186,7 +1186,7 @@ nsContextMenu.prototype = {
 
   // Save URL of clicked-on frame.
   saveFrame: function () {
-    saveDocument(this.target.ownerDocument);
+    saveBrowser(this.browser, false, this.frameOuterWindowID);
   },
 
   // Helper function to wait for appropriate MIME-type headers and

dom/base/nsContentUtils.cpp

@@ -3849,6 +3849,30 @@ nsContentUtils::MatchElementId(nsIContent *aContent, const nsAString& aId)
   return MatchElementId(aContent, id);
 }
 
+/* static */
+nsIDocument*
+nsContentUtils::GetSubdocumentWithOuterWindowId(nsIDocument *aDocument,
+                                                uint64_t aOuterWindowId)
+{
+  if (!aDocument || !aOuterWindowId) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsPIDOMWindow> window = nsGlobalWindow::GetOuterWindowWithId(aOuterWindowId);
+  if (!window) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsIDocument> foundDoc = window->GetDoc();
+  if (nsContentUtils::ContentIsCrossDocDescendantOf(foundDoc, aDocument)) {
+    // Note that ContentIsCrossDocDescendantOf will return true if
+    // foundDoc == aDocument.
+    return foundDoc;
+  }
+
+  return nullptr;
+}
+
 // Convert the string from the given encoding to Unicode.
 /* static */
 nsresult

dom/base/nsContentUtils.h

@@ -325,6 +325,23 @@ public:
    */
   static uint16_t ReverseDocumentPosition(uint16_t aDocumentPosition);
 
+  /**
+   * Returns a subdocument for aDocument with a particular outer window ID.
+   *
+   * @param aDocument
+   *        The document whose subdocuments will be searched.
+   * @param aOuterWindowID
+   *        The outer window ID for the subdocument to be found. This must
+   *        be a value greater than 0.
+   * @return nsIDocument*
+   *        A pointer to the found nsIDocument. nullptr if the subdocument
+   *        cannot be found, or if either aDocument or aOuterWindowId were
+   *        invalid. If the outer window ID belongs to aDocument itself, this
+   *        will return a pointer to aDocument.
+   */
+  static nsIDocument* GetSubdocumentWithOuterWindowId(nsIDocument *aDocument,
+                                                      uint64_t aOuterWindowId);
+
   static uint32_t CopyNewlineNormalizedUnicodeTo(const nsAString& aSource,
                                                  uint32_t aSrcOffset,
                                                  char16_t* aDest,

dom/base/nsFrameLoader.cpp

@@ -2885,18 +2885,31 @@ nsFrameLoader::InitializeBrowserAPI()
 }
 
 NS_IMETHODIMP
-nsFrameLoader::StartPersistence(nsIWebBrowserPersistDocumentReceiver* aRecv)
+nsFrameLoader::StartPersistence(uint64_t aOuterWindowID,
+                                nsIWebBrowserPersistDocumentReceiver* aRecv)
 {
+  if (!aRecv) {
+    return NS_ERROR_INVALID_POINTER;
+  }
+
   if (mRemoteBrowser) {
-    return mRemoteBrowser->StartPersistence(aRecv);
+    return mRemoteBrowser->StartPersistence(aOuterWindowID, aRecv);
   }
-  if (mDocShell) {
-    nsCOMPtr<nsIDocument> doc = do_GetInterface(mDocShell);
-    NS_ENSURE_STATE(doc);
+
+  nsCOMPtr<nsIDocument> rootDoc = do_GetInterface(mDocShell);
+  nsCOMPtr<nsIDocument> foundDoc;
+  if (aOuterWindowID) {
+    foundDoc = nsContentUtils::GetSubdocumentWithOuterWindowId(rootDoc, aOuterWindowID);
+  } else {
+    foundDoc = rootDoc;
+  }
+
+  if (!foundDoc) {
+    aRecv->OnError(NS_ERROR_NO_CONTENT);
+  } else {
     nsCOMPtr<nsIWebBrowserPersistDocument> pdoc =
-      new mozilla::WebBrowserPersistLocalDocument(doc);
+      new mozilla::WebBrowserPersistLocalDocument(foundDoc);
     aRecv->OnDocumentReady(pdoc);
-    return NS_OK;
   }
-  return NS_ERROR_NO_CONTENT;
+  return NS_OK;
 }

dom/ipc/PBrowser.ipdl

@@ -121,7 +121,7 @@ both:
      */
     PRenderFrame();
 
-    PWebBrowserPersistDocument();
+    PWebBrowserPersistDocument(uint64_t aOuterWindowID);
 
 parent:
     /**
@@ -524,6 +524,7 @@ parent:
 child:
     NativeSynthesisResponse(uint64_t aObserverId, nsCString aResponse);
 
+
 parent:
 
     /**

dom/ipc/TabChild.cpp

@@ -3118,16 +3118,28 @@ TabChildGlobal::GetGlobalJSObject()
 }
 
 PWebBrowserPersistDocumentChild*
-TabChild::AllocPWebBrowserPersistDocumentChild()
+TabChild::AllocPWebBrowserPersistDocumentChild(const uint64_t& aOuterWindowID)
 {
   return new WebBrowserPersistDocumentChild();
 }
 
 bool
-TabChild::RecvPWebBrowserPersistDocumentConstructor(PWebBrowserPersistDocumentChild *aActor)
+TabChild::RecvPWebBrowserPersistDocumentConstructor(PWebBrowserPersistDocumentChild *aActor,
+                                                    const uint64_t& aOuterWindowID)
 {
-  nsCOMPtr<nsIDocument> doc = GetDocument();
-  static_cast<WebBrowserPersistDocumentChild*>(aActor)->Start(doc);
+  nsCOMPtr<nsIDocument> rootDoc = GetDocument();
+  nsCOMPtr<nsIDocument> foundDoc;
+  if (aOuterWindowID) {
+    foundDoc = nsContentUtils::GetSubdocumentWithOuterWindowId(rootDoc, aOuterWindowID);
+  } else {
+    foundDoc = rootDoc;
+  }
+
+  if (!foundDoc) {
+    aActor->SendInitFailure(NS_ERROR_NO_CONTENT);
+  } else {
+    static_cast<WebBrowserPersistDocumentChild*>(aActor)->Start(foundDoc);
+  }
   return true;
 }
 

dom/ipc/TabChild.h

@@ -495,8 +495,9 @@ public:
 
     virtual ScreenIntSize GetInnerSize() override;
 
-    virtual PWebBrowserPersistDocumentChild* AllocPWebBrowserPersistDocumentChild() override;
-    virtual bool RecvPWebBrowserPersistDocumentConstructor(PWebBrowserPersistDocumentChild *aActor) override;
+    virtual PWebBrowserPersistDocumentChild* AllocPWebBrowserPersistDocumentChild(const uint64_t& aOuterWindowID) override;
+    virtual bool RecvPWebBrowserPersistDocumentConstructor(PWebBrowserPersistDocumentChild *aActor,
+                                                           const uint64_t& aOuterWindowID) override;
     virtual bool DeallocPWebBrowserPersistDocumentChild(PWebBrowserPersistDocumentChild* aActor) override;
 
 protected:

dom/ipc/TabParent.cpp

@@ -3368,7 +3368,7 @@ TabParent::AsyncPanZoomEnabled() const
 }
 
 PWebBrowserPersistDocumentParent*
-TabParent::AllocPWebBrowserPersistDocumentParent()
+TabParent::AllocPWebBrowserPersistDocumentParent(const uint64_t& aOuterWindowID)
 {
   return new WebBrowserPersistDocumentParent();
 }
@@ -3381,11 +3381,12 @@ TabParent::DeallocPWebBrowserPersistDocumentParent(PWebBrowserPersistDocumentPar
 }
 
 NS_IMETHODIMP
-TabParent::StartPersistence(nsIWebBrowserPersistDocumentReceiver* aRecv)
+TabParent::StartPersistence(uint64_t aOuterWindowID,
+                            nsIWebBrowserPersistDocumentReceiver* aRecv)
 {
   auto* actor = new WebBrowserPersistDocumentParent();
   actor->SetOnReady(aRecv);
-  return SendPWebBrowserPersistDocumentConstructor(actor)
+  return SendPWebBrowserPersistDocumentConstructor(actor, aOuterWindowID)
     ? NS_OK : NS_ERROR_FAILURE;
   // (The actor will be destroyed on constructor failure.)
 }

dom/ipc/TabParent.h

@@ -435,7 +435,7 @@ public:
                                int32_t& aDragAreaX, int32_t& aDragAreaY);
     layout::RenderFrameParent* GetRenderFrame();
 
-    virtual PWebBrowserPersistDocumentParent* AllocPWebBrowserPersistDocumentParent() override;
+    virtual PWebBrowserPersistDocumentParent* AllocPWebBrowserPersistDocumentParent(const uint64_t& aOuterWindowID) override;
     virtual bool DeallocPWebBrowserPersistDocumentParent(PWebBrowserPersistDocumentParent* aActor) override;
 
 protected:

embedding/components/webbrowserpersist/WebBrowserPersistLocalDocument.cpp

@@ -346,7 +346,10 @@ ResourceReader::OnWalkSubframe(nsIDOMNode* aNode)
     NS_ENSURE_STATE(loader);
 
     ++mOutstandingDocuments;
-    nsresult rv = loader->StartPersistence(this);
+    // Pass in 0 as the outer window ID so that we start
+    // persisting the root of this subframe, and not some other
+    // subframe child of this subframe.
+    nsresult rv = loader->StartPersistence(0, this);
     if (NS_FAILED(rv)) {
         if (rv == NS_ERROR_NO_CONTENT) {
             // Just ignore frames with no content document.

embedding/components/webbrowserpersist/WebBrowserPersistResourcesChild.cpp

@@ -37,7 +37,11 @@ WebBrowserPersistResourcesChild::VisitDocument(nsIWebBrowserPersistDocument* aDo
 {
     auto* subActor = new WebBrowserPersistDocumentChild();
     dom::PBrowserChild* grandManager = Manager()->Manager();
-    if (!grandManager->SendPWebBrowserPersistDocumentConstructor(subActor)) {
+    // As a consequence of how PWebBrowserPersistDocumentConstructor can be
+    // sent by both the parent and the child, we must pass the outerWindowID
+    // argument here. We pass 0, though note that this argument is actually
+    // just ignored when passed up to the parent from the child.
+    if (!grandManager->SendPWebBrowserPersistDocumentConstructor(subActor, 0)) {
         // NOTE: subActor is freed at this point.
         return NS_ERROR_FAILURE;
     }

embedding/components/webbrowserpersist/nsIWebBrowserPersistable.idl

@@ -22,9 +22,20 @@ interface nsIWebBrowserPersistDocumentReceiver;
  * @see nsIWebBrowserPersistDocumentReceiver
  * @see nsIWebBrowserPersistDocument
  * @see nsIWebBrowserPersist
+ *
+ * @param aOuterWindowID
+ *        The outer window ID of the subframe we'd like to persist.
+ *        If set at 0, nsIWebBrowserPersistable will attempt to persist
+ *        the top-level document. If the outer window ID is for a subframe
+ *        that does not exist, or is not held beneath the nsIWebBrowserPersistable,
+ *        aRecv's onError method will be called with NS_ERROR_NO_CONTENT.
+ * @param aRecv
+ *        The nsIWebBrowserPersistDocumentReceiver is a callback that
+ *        will be fired once the document is ready for persisting.
  */
-[scriptable, function, uuid(24d0dc9e-b970-4cca-898f-cbba03abaa73)]
+[scriptable, uuid(f4c3fa8e-83e9-49f8-ac6f-951fc7541fe4)]
 interface nsIWebBrowserPersistable : nsISupports
 {
-  void startPersistence(in nsIWebBrowserPersistDocumentReceiver aRecv);
+  void startPersistence(in unsigned long long aOuterWindowID,
+                        in nsIWebBrowserPersistDocumentReceiver aRecv);
 };

toolkit/content/contentAreaUtils.js

@@ -129,7 +129,7 @@ function saveImageURL(aURL, aFileName, aFilePickerTitleKey, aShouldBypassCache,
 // This is like saveDocument, but takes any browser/frame-like element
 // (nsIFrameLoaderOwner) and saves the current document inside it,
 // whether in-process or out-of-process.
-function saveBrowser(aBrowser, aSkipPrompt)
+function saveBrowser(aBrowser, aSkipPrompt, aOuterWindowID=0)
 {
   if (!aBrowser) {
     throw "Must have a browser when calling saveBrowser";
@@ -138,7 +138,7 @@ function saveBrowser(aBrowser, aSkipPrompt)
                     .frameLoader
                     .QueryInterface(Ci.nsIWebBrowserPersistable);
   let stack = Components.stack.caller;
-  persistable.startPersistence({
+  persistable.startPersistence(aOuterWindowID, {
     onDocumentReady: function (document) {
       saveDocument(document, aSkipPrompt);
     },