views: Extract Widget observer into its own header file.

chrome/browser/ui/views/frame/browser_frame.cc

 // 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.
 
 #include "chrome/browser/ui/views/frame/browser_frame.h"
 
 #include "base/chromeos/chromeos_version.h"
 #include "base/i18n/rtl.h"
 #include "chrome/browser/themes/theme_service.h"
 #include "chrome/browser/themes/theme_service_factory.h"
@@ skipping 118 matching lines @@
   }
 #endif
   return browser_frame_view_;
 }
 
 bool BrowserFrame::GetAccelerator(int command_id,
                                   ui::Accelerator* accelerator) {
   return browser_view_->GetAccelerator(command_id, accelerator);
 }
 
-ThemeProvider* BrowserFrame::GetThemeProvider() const {
+ui::ThemeProvider* BrowserFrame::GetThemeProvider() const {
   return ThemeServiceFactory::GetForProfile(
       browser_view_->browser()->profile());
 }
 
 void BrowserFrame::OnNativeWidgetActivationChanged(bool active) {
   if (active) {
     // When running under remote desktop, if the remote desktop client is not
     // active on the users desktop, then none of the windows contained in the
     // remote desktop will be activated.  However, NativeWidgetWin::Activate()
     // will still bring this browser window to the foreground.  We explicitly
     // set ourselves as the last active browser window to ensure that we get
     // treated as such by the rest of Chrome.
     BrowserList::SetLastActive(browser_view_->browser());
   }
   Widget::OnNativeWidgetActivationChanged(active);
 }
 
 AvatarMenuButton* BrowserFrame::GetAvatarMenuButton() {
   return browser_frame_view_->avatar_button();
 }