Fix hung renderer timer code in RenderWidgetHost (task spam bug)

content/browser/renderer_host/render_widget_host.h

 // Copyright (c) 2011 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_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_H_
 #pragma once
 
 #include <deque>
 #include <string>
@@ skipping 694 matching lines @@
 
   // If true, then we should repaint when restoring even if we have a
   // backingstore.  This flag is set to true if we receive a paint message
   // while is_hidden_ to true.  Even though we tell the render widget to hide
   // itself, a paint message could already be in flight at that point.
   bool needs_repainting_on_restore_;
 
   // This is true if the renderer is currently unresponsive.
   bool is_unresponsive_;
 
-  // The following value indicates a time in the future when we would consider
-  // the renderer hung if it does not generate an appropriate response message.
-  base::Time time_when_considered_hung_;
+  // This is true if we are currently monitoring for a hung renderer.
+  bool is_monitoring_for_hung_renderer_;
 
-  // This timer runs to check if time_when_considered_hung_ has past.
+  // Last time we heard from the renderer.
+  base::TimeTicks time_of_last_renderer_response_;
+
+  // This timer runs to check if the renderer is unresponsive.
   base::OneShotTimer<RenderWidgetHost> hung_renderer_timer_;
 
   // Flag to detect recursive calls to GetBackingStore().
   bool in_get_backing_store_;
 
   // Set when we call DidPaintRect/DidScrollRect on the view.
   bool view_being_painted_;
 
   // Used for UMA histogram logging to measure the time for a repaint view
   // operation to finish.
@@ skipping 40 matching lines @@
   gfx::Point last_scroll_offset_;
 
   bool pending_mouse_lock_request_;
 
   base::WeakPtrFactory<RenderWidgetHost> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHost);
 };
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_H_