Support frame tree propagation between renderers in the same browsing instance.

content/renderer/render_view_impl.h

Index: content/renderer/render_view_impl.h
diff --git a/content/renderer/render_view_impl.h b/content/renderer/render_view_impl.h
index 04490b93e27b795c3d976fd89974f0a4f0e75040..0fab6d3497c6811c6c9515a03971c80f7691c767 100644
--- a/content/renderer/render_view_impl.h
+++ b/content/renderer/render_view_impl.h
@@ -18,6 +18,7 @@
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/timer.h"
+#include "base/values.h"
 #include "build/build_config.h"
 #include "content/common/content_export.h"
 #include "content/common/edit_command.h"
@@ -527,6 +528,8 @@ class RenderViewImpl : public RenderWidget,
       WebKit::WebFrame* frame,
       WebKit::WebApplicationCacheHostClient* client);
   virtual WebKit::WebCookieJar* cookieJar(WebKit::WebFrame* frame);
+  virtual void didCreateFrame(WebKit::WebFrame* parent,
+                              WebKit::WebFrame* child);
   virtual void frameDetached(WebKit::WebFrame* frame);
   virtual void willClose(WebKit::WebFrame* frame);
   virtual void loadURLExternally(WebKit::WebFrame* frame,
@@ -665,7 +668,8 @@ class RenderViewImpl : public RenderWidget,
   virtual void willOpenSocketStream(
       WebKit::WebSocketStreamHandle* handle);
   virtual bool willCheckAndDispatchMessageEvent(
-      WebKit::WebFrame* source,
+      WebKit::WebFrame* sourceFrame,
+      WebKit::WebFrame* targetFrame,
       WebKit::WebSecurityOrigin targetOrigin,
       WebKit::WebDOMMessageEvent event) OVERRIDE;
   virtual WebKit::WebString userAgentOverride(
@@ -1027,6 +1031,10 @@ class RenderViewImpl : public RenderWidget,
 
   void OnJavaBridgeInit();
 
+  void OnUpdatedFrameTree(int process_id,
+                          int route_id,
+                          const std::string& frame_tree);
+
   // Adding a new message handler? Please add it in alphabetical order above
   // and put it in the same position in the .cc file.
 
@@ -1044,6 +1052,15 @@ class RenderViewImpl : public RenderWidget,
   WebKit::WebGraphicsContext3D* CreateGraphicsContext3D(
       const WebKit::WebGraphicsContext3D::Attributes& attributes);
 
+  // This method walks the entire frame tree for the |frame| specified and
+  // sends an update to the browser process as described in the
+  // ViewHostMsg_FrameTreeUpdated comments.
+  void SendUpdatedFrameTree(WebKit::WebFrame* frame, bool exclude);

[Charlie Reis, 2012/08/22 22:08:34]

What's |exclude| about?

[nasko, 2012/08/23 21:55:53]

Done.

+
+  // Walks the frame hierarchy and returns the frame which corresponds to the
+  // |remote_frame_id|.

[Charlie Reis, 2012/08/22 22:08:34]

I don't understand what remote_frame_id is referring to.  Is this the frame ID
of the corresponding frame in the active process, when this RenderView is
swapped out?  We should be more explicit.

[nasko, 2012/08/23 21:55:53]

I've renamed it from Remote to Mapped. The idea of this function is to find the
frame through the frame mapping. In an essence, we are doing translation of ids
and look up based on that translation.

+  WebKit::WebFrame* GetFrameByRemoteID(int remote_frame_id);
+
   void EnsureMediaStreamImpl();
 
   // This callback is triggered when DownloadFavicon completes, either
@@ -1087,7 +1104,8 @@ class RenderViewImpl : public RenderWidget,
                                    bool replace);
 
   // Make this RenderView show an empty, unscriptable page.

[Charlie Reis, 2012/08/22 22:08:34]

Please update the comment for what the parameters mean.

[nasko, 2012/08/23 21:55:53]

Done.

-  void NavigateToSwappedOutURL();
+  void NavigateToSwappedOutURL(WebKit::WebFrame* frame,
+                               DictionaryValue* frame_tree);
 
   // If we initiated a navigation, this function will populate |document_state|
   // with the navigation information saved in OnNavigate().
@@ -1438,6 +1456,25 @@ class RenderViewImpl : public RenderWidget,
   // before the guest_to_embedder_channel was ready.
   WebKit::WebGraphicsContext3D::Attributes guest_attributes_;
 
+  // Boolean indicating whether we are in the process of updating the frame
+  // tree for this renderer. If true, we won't be sending frame tree updates

[Charlie Reis, 2012/08/22 22:08:34]

nit: renderer -> RenderView.

"Updating the frame tree" is a bit of an overloaded term at this point.  I was
originally reading it as "letting the browser process know what our frame tree
is" rather than "recreating the current frame tree from the active RenderView,
given that this is a swapped out RenderView."  Can you make this clearer?

[nasko, 2012/08/23 21:55:53]

Done.

+  // back to the browser.
+  bool updating_frame_tree_;
+
+  // Boolean indicating that the frame tree has changed, but message has not

[Charlie Reis, 2012/08/22 22:08:34]

nit: a message

[nasko, 2012/08/23 21:55:53]

Done.

+  // been sent to the browser because a resource has been loading.

[Charlie Reis, 2012/08/22 22:08:34]

Why does a loading resource block us?

[nasko, 2012/08/23 21:55:53]

Loading a resource doesn't block us. This is to avoid all the updates we will be
sending when navigating away from a page with a bunch of frames. Added a comment
to clarify it.

+  bool pending_frame_tree_update_;
+
+  // If this render view is swapped out mirror of an active render view in a

[Charlie Reis, 2012/08/22 22:08:34]

nit: is the swapped out "mirror"

[nasko, 2012/08/23 21:55:53]

Done.

+  // different process, we record the process id and route id for the active RV.
+  // For further details, see the comments on ViewHostMsg_FrameTreeUpdated.
+  int target_process_id_;
+  int target_routing_id_;
+
+  // A mapping of current process frame ids to ids in the remote active render

[Charlie Reis, 2012/08/22 22:08:34]

nit: A map of the current process's

[nasko, 2012/08/23 21:55:53]

Done.

+  // view, if this is a swapped out mirror render view.

[Charlie Reis, 2012/08/22 22:08:34]

nit: We don't need to say mirror here.

[nasko, 2012/08/23 21:55:53]

Done.

+  std::map<int, int> frames_map_;

[Charlie Reis, 2012/08/22 22:08:34]

This name could be more descriptive.  active_frame_id_map_, perhaps?

[nasko, 2012/08/23 21:55:53]

Done.

+
   // NOTE: pepper_delegate_ should be last member because its constructor calls
   // AddObservers method of RenderViewImpl from c-tor.
   content::PepperPluginDelegateImpl pepper_delegate_;