Enable swapping a frame back in to its parent process

content/renderer/render_frame_impl.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_RENDER_FRAME_IMPL_H_
 #define CONTENT_RENDERER_RENDER_FRAME_IMPL_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 86 matching lines @@
   // Creates a new RenderFrame. |render_view| is the RenderView object that this
   // frame belongs to.
   // Callers *must* call |SetWebFrame| immediately after creation.
   // Note: This is called only when RenderFrame is created by Blink through
   // createChildFrame.
   // TODO(creis): We should structure this so that |SetWebFrame| isn't needed.
   static RenderFrameImpl* Create(RenderViewImpl* render_view, int32 routing_id);
 
   // Creates a new RenderFrame with |routing_id| as a child of the RenderFrame
   // identified by |parent_routing_id| or as the top-level frame if the latter
-  // is MSG_ROUTING_NONE. It creates the Blink WebLocalFrame and inserts it in
-  // the proper place in the frame tree.
+  // is MSG_ROUTING_NONE. If proxy_routing_id is MSG_ROUTING_NONE, it creates
+  // the Blink WebLocalFrame and inserts it in the proper place in the frame
+  // tree. Otherwise, the frame is semi-orphaned until it commits, at which
+  // point it replaces the given proxy.

[nasko, 2014/10/27 22:52:55]

nit: s/the given proxy/the proxy identified by |proxy_routing_id|/

[Nate Chapin, 2014/10/28 19:59:20]

Done.

   // Note: This is called only when RenderFrame is being created in response to
   // IPC message from the browser process. All other frame creation is driven
   // through Blink and Create.
-  static void CreateFrame(int routing_id, int parent_routing_id);
+  static void CreateFrame(int routing_id,
+                          int parent_routing_id,
+                          int proxy_routing_id);
 
   // Returns the RenderFrameImpl for the given routing ID.
   static RenderFrameImpl* FromRoutingID(int routing_id);
 
   // Just like RenderFrame::FromWebFrame but returns the implementation.
   static RenderFrameImpl* FromWebFrame(blink::WebFrame* web_frame);
 
   // Used by content_layouttest_support to hook into the creation of
   // RenderFrameImpls.
   static void InstallCreateHook(
@@ skipping 540 matching lines @@
 
   base::WeakPtr<RenderViewImpl> render_view_;
   int routing_id_;
   bool is_swapped_out_;
   // RenderFrameProxy exists only when is_swapped_out_ is true.
   // TODO(nasko): This can be removed once we don't have a swapped out state on
   // RenderFrame. See https://crbug.com/357747.
   RenderFrameProxy* render_frame_proxy_;
   bool is_detaching_;
 
+  // If this frame was created to replace a proxy, this will store the routing
+  // id of the proxy to replace at commit-time.

[Charlie Reis, 2014/10/28 16:38:29]

Unfortunate that we have to store this.  I suppose it will go away with
PlzNavigate, though, since we won't need the RenderFrameImpl until commit time.

Can you clarify that this is cleared at commit time?

[Nate Chapin, 2014/10/28 19:59:20]

Done.

+  int proxy_routing_id_;
+
 #if defined(ENABLE_PLUGINS)
   // Current text input composition text. Empty if no composition is in
   // progress.
   base::string16 pepper_composition_text_;
 #endif
 
   RendererWebCookieJarImpl cookie_jar_;
 
   // All the registered observers.
   ObserverList<RenderFrameObserver> observers_;
@@ skipping 97 matching lines @@
 #endif
 
   base::WeakPtrFactory<RenderFrameImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_FRAME_IMPL_H_