Give the main frame a RenderWidget.

content/renderer/render_widget.h

 // Copyright (c) 2012 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_WIDGET_H_
 #define CONTENT_RENDERER_RENDER_WIDGET_H_
 
 #include <deque>
 #include <map>
 
@@ skipping 100 matching lines @@
                               const blink::WebScreenInfo& screen_info);
 
   // Creates a new RenderWidget that will be attached to a RenderFrame.
   static RenderWidget* CreateForFrame(int routing_id,
                                       bool hidden,
                                       const blink::WebScreenInfo& screen_info,
                                       CompositorDependencies* compositor_deps,
                                       blink::WebLocalFrame* frame);
 
   // Closes a RenderWidget that was created by |CreateForFrame|.
-  void CloseForFrame();
+  // TODO(avi): De-virtualize this once RenderViewImpl has-a RenderWidget.
+  // https://crbug.com/545684
+  virtual void CloseForFrame();
 
   int32 routing_id() const { return routing_id_; }
   CompositorDependencies* compositor_deps() const { return compositor_deps_; }
   blink::WebWidget* webwidget() const { return webwidget_; }
   gfx::Size size() const { return size_; }
   bool is_fullscreen_granted() const { return is_fullscreen_granted_; }
   blink::WebDisplayMode display_mode() const { return display_mode_; }
   bool is_hidden() const { return is_hidden_; }
   bool handling_input_event() const { return handling_input_event_; }
   // Temporary for debugging purposes...
@@ skipping 656 matching lines @@
   ui::MenuSourceType context_menu_source_type_;
   bool has_host_context_menu_location_;
   gfx::Point host_context_menu_location_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_WIDGET_H_