Make <webview> use out-of-process iframe architecture.

components/guest_view/renderer/guest_view_container.h

Index: components/guest_view/renderer/guest_view_container.h
diff --git a/components/guest_view/renderer/guest_view_container.h b/components/guest_view/renderer/guest_view_container.h
index 19175b9c787d6417a4b4dac5e404bae67a411b4a..f9dec5452d8d9e28728e202454a6e18d31bdb38b 100644
--- a/components/guest_view/renderer/guest_view_container.h
+++ b/components/guest_view/renderer/guest_view_container.h
@@ -39,6 +39,14 @@ class GuestViewContainer : public content::BrowserPluginDelegate {
   // Called to perform actions when a GuestViewContainer gets a geometry.
   virtual void OnReady() {}
 
+  // BrowserPluginGuestDelegate public implementation.
+  void SetElementInstanceID(int element_instance_id) final;
+
+ protected:
+  bool ready_;
+
+  void OnHandleCallback(const IPC::Message& message);
+
  private:
   class RenderFrameLifetimeObserver;
   friend class RenderFrameLifetimeObserver;
@@ -49,19 +57,14 @@ class GuestViewContainer : public content::BrowserPluginDelegate {
   void PerformPendingRequest();
   void HandlePendingResponseCallback(const IPC::Message& message);
 
-  void OnHandleCallback(const IPC::Message& message);
-
   // BrowserPluginDelegate implementation.
   bool OnMessageReceived(const IPC::Message& message) final;
   void Ready() final;
-  void SetElementInstanceID(int element_instance_id) final;
 
   int element_instance_id_;
   content::RenderFrame* render_frame_;
   scoped_ptr<RenderFrameLifetimeObserver> render_frame_lifetime_observer_;
 
-  bool ready_;
-
   std::deque<linked_ptr<GuestViewRequest> > pending_requests_;
   linked_ptr<GuestViewRequest> pending_response_;