Clear renderer compositor trees if new page does not render in 4 seconds

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 <stddef.h>
 #include <stdint.h>
 
@@ skipping 396 matching lines @@
 
   // When emulated, this returns original device scale factor.
   float GetOriginalDeviceScaleFactor() const;
 
   // Helper to convert |point| using ConvertWindowToViewport().
   gfx::Point ConvertWindowPointToViewport(const gfx::Point& point);
 
   virtual void TransferActiveWheelFlingAnimation(
       const blink::WebActiveWheelFlingParameters& params) {}
 
+  void OnClearDisplayedContent();
+
  protected:
   // Friend RefCounted so that the dtor can be non-public. Using this class
   // without ref-counting is an error.
   friend class base::RefCounted<RenderWidget>;
 
   // For unit tests.
   friend class RenderWidgetTest;
 
   enum ResizeAck {
     SEND_RESIZE_ACK,
@@ skipping 421 matching lines @@
   base::TimeTicks was_shown_time_;
 
   base::WeakPtrFactory<RenderWidget> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_WIDGET_H_