Change how ui::Clipboard is accessed so there's only one per thread.

ui/views/views_delegate.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 UI_VIEWS_VIEWS_DELEGATE_H_
 #define UI_VIEWS_VIEWS_DELEGATE_H_
 
 #include <string>
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
 
 #include "base/string16.h"
 #include "ui/base/accessibility/accessibility_types.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/views/views_export.h"
 
 namespace content {
 class WebContents;
 class BrowserContext;
 class SiteInstance;
 }
 
 namespace gfx {
 class Rect;
 }
 
-namespace ui {
-class Clipboard;
-}
-
 namespace views {
 
 class NonClientFrameView;
 class View;
 class Widget;
 
 #if defined(USE_AURA)
 class NativeWidgetAura;
 class NativeWidgetHelperAura;
 #endif
 
 // ViewsDelegate is an interface implemented by an object using the views
 // framework. It is used to obtain various high level application utilities
 // and perform some actions such as window placement saving.
 //
 // The embedding app must set views_delegate to assign its ViewsDelegate
 // implementation.
 class VIEWS_EXPORT ViewsDelegate {
  public:
   // The active ViewsDelegate used by the views system.
   static ViewsDelegate* views_delegate;
 
   virtual ~ViewsDelegate() {}
 
-  // Gets the clipboard.
-  virtual ui::Clipboard* GetClipboard() const = 0;
-
   // Saves the position, size and "show" state for the window with the
   // specified name.
   virtual void SaveWindowPlacement(const Widget* widget,
                                    const std::string& window_name,
                                    const gfx::Rect& bounds,
                                    ui::WindowShowState show_state) = 0;
 
   // Retrieves the saved position and size and "show" state for the window with
   // the specified name.
   virtual bool GetSavedWindowPlacement(
@@ skipping 46 matching lines @@
 
   // Creates a web contents. This will return NULL unless overriden.
   virtual content::WebContents* CreateWebContents(
       content::BrowserContext* browser_context,
       content::SiteInstance* site_instance) = 0;
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_VIEWS_DELEGATE_H_