Allow RenderFrames to swap out for subframe navigations.

content/renderer/render_frame_impl.h

Index: content/renderer/render_frame_impl.h
diff --git a/content/renderer/render_frame_impl.h b/content/renderer/render_frame_impl.h
index 53fddbe0884e859d861ac036fe3be540f44a87c4..274c5970bd6a041669bd16ddd15c7b10e28b2af0 100644
--- a/content/renderer/render_frame_impl.h
+++ b/content/renderer/render_frame_impl.h
@@ -47,8 +47,17 @@ class CONTENT_EXPORT RenderFrameImpl
  public:
   // Creates a new RenderFrame. |render_view| is the RenderView object that this
   // frame belongs to.
+  // Callers *must* call |SetWebFrame| immediately after creation.
+  // TODO(creis): We should structure this so that |SetWebFrame| isn't needed.
   static RenderFrameImpl* Create(RenderViewImpl* render_view, int32 routing_id);
 
+  // For subframes, look up the RenderFrameImpl for the given WebFrame.  Returns
+  // NULL for main frames.
+  // This only works when using --site-per-process, and returns NULL otherwise.
+  // TODO(creis): Remove this when the RenderView methods dealing with frames
+  // have moved to RenderFrame.
+  static RenderFrameImpl* FindByWebFrame(blink::WebFrame* web_frame);
+
   // Used by content_layouttest_support to hook into the creation of
   // RenderFrameImpls.
   static void InstallCreateHook(
@@ -56,6 +65,10 @@ class CONTENT_EXPORT RenderFrameImpl
 
   virtual ~RenderFrameImpl();
 
+  bool is_swapped_out() const {
+    return is_swapped_out_;
+  }
+
   // TODO(jam): this is a temporary getter until all the code is transitioned
   // to using RenderFrame instead of RenderView.
   RenderViewImpl* render_view() { return render_view_; }
@@ -69,6 +82,10 @@ class CONTENT_EXPORT RenderFrameImpl
   // blink::WebFrame has been created.
   void MainWebFrameCreated(blink::WebFrame* frame);
 
+  // In --site-per-process mode, we keep track of which WebFrame this
+  // RenderFrameImpl is for.
+  void SetWebFrame(blink::WebFrame* web_frame);
+
 #if defined(ENABLE_PLUGINS)
   // Notification that a PPAPI plugin has been created.
   void PepperPluginCreated(RendererPpapiHost* host);
@@ -329,6 +346,16 @@ class CONTENT_EXPORT RenderFrameImpl
   void AddObserver(RenderFrameObserver* observer);
   void RemoveObserver(RenderFrameObserver* observer);
 
+  // IPC message handlers ------------------------------------------------------
+  //
+  // The documentation for these functions should be in
+  // content/common/*_messages.h for the message that the function is handling.
+  void OnSwapOut();
+
+  // In --site-per-process mode, stores the WebFrame we are associated with.
+  // NULL otherwise.
+  blink::WebFrame* frame_;
+
   RenderViewImpl* render_view_;
   int routing_id_;
   bool is_swapped_out_;