Modify the RenderThread to track the number of widgets...

chrome/renderer/mock_render_thread.h

 // Copyright (c) 2009 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 CHROME_RENDERER_MOCK_RENDER_THREAD_H_
 #define CHROME_RENDERER_MOCK_RENDER_THREAD_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 23 matching lines @@
 
   // Called by the Widget. The routing id must match the routing id of AddRoute.
   virtual void RemoveRoute(int32 routing_id);
 
   // Called by the Widget. Used to send messages to the browser.
   // We short-circuit the mechanim and handle the messages right here on this
   // class.
   virtual bool Send(IPC::Message* msg);
 
   // Our mock thread doesn't do filtering.
-  virtual void AddFilter(IPC::ChannelProxy::MessageFilter* filter) {
-  }
-  virtual void RemoveFilter(IPC::ChannelProxy::MessageFilter* filter) {
-  }
+  virtual void AddFilter(IPC::ChannelProxy::MessageFilter* filter) { }
+  virtual void RemoveFilter(IPC::ChannelProxy::MessageFilter* filter) { }
+
+  // Our mock thread doesn't deal with hidden and restored tabs.
+  virtual void WidgetHidden() { }
+  virtual void WidgetRestored() { }
 
   //////////////////////////////////////////////////////////////////////////
   // The following functions are called by the test itself.
 
   void set_routing_id(int32 id) {
     routing_id_ = id;
   }
 
   int32 opener_id() const {
     return opener_id_;
@@ skipping 51 matching lines @@
   IPC::Channel::Listener* widget_;
 
   // The last known good deserializer for sync messages.
   scoped_ptr<IPC::MessageReplyDeserializer> reply_deserializer_;
 
   // A mock printer device used for printing tests.
   scoped_ptr<MockPrinter> printer_;
 };
 
 #endif  // CHROME_RENDERER_MOCK_RENDER_THREAD_H_