Only allow to lock the mouse when the tab is in fullscreen mode.

content/browser/tab_contents/tab_contents_delegate.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_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_
 #define CONTENT_BROWSER_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_
 #pragma once
 
 #include <set>
 #include <string>
@@ skipping 301 matching lines @@
 
   // Request to enumerate a directory.  This is equivalent to running the file
   // chooser in directory-enumeration mode and having the user select the given
   // directory.
   virtual void EnumerateDirectory(TabContents* tab, int request_id,
                                   const FilePath& path);
 
   // Called when the renderer puts a tab into or out of fullscreen mode.
   virtual void ToggleFullscreenModeForTab(TabContents* tab,
                                           bool enter_fullscreen);
+  virtual bool IsFullscreenForTab(const TabContents* tab) const;
 
   // Called when a Javascript out of memory notification is received.
   virtual void JSOutOfMemory(TabContents* tab);
 
   // Register a new handler for URL requests with the given scheme.
   virtual void RegisterProtocolHandler(TabContents* tab,
                                        const std::string& protocol,
                                        const GURL& url,
                                        const string16& title);
 
@@ skipping 37 matching lines @@
   void Attach(TabContents* source);
 
   // Called when |this| is no longer the TabContentsDelegate for |source|.
   void Detach(TabContents* source);
 
   // The TabContents that this is currently a delegate for.
   std::set<TabContents*> attached_contents_;
 };
 
 #endif  // CONTENT_BROWSER_TAB_CONTENTS_TAB_CONTENTS_DELEGATE_H_