Remove windows/mac/ios specific code from //ui

ui/gl/gpu_switching_manager.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_GL_GPU_SWITCHING_MANAGER_H_
 #define UI_GL_GPU_SWITCHING_MANAGER_H_
 
 #include <vector>
 
 #include "base/memory/singleton.h"
@@ skipping 36 matching lines @@
   // in the browser process only so that any workarounds or blacklisting can
   // be applied there.
   void NotifyGpuSwitched();
 
  private:
   friend struct DefaultSingletonTraits<GpuSwitchingManager>;
 
   GpuSwitchingManager();
   virtual ~GpuSwitchingManager();
 
-#if defined(OS_MACOSX)
-  void SwitchToDiscreteGpuMac();
-#endif  // OS_MACOSX
-
   gfx::GpuPreference gpu_switching_option_;
   bool gpu_switching_option_set_;
 
   bool supports_dual_gpus_;
   bool supports_dual_gpus_set_;
 
   size_t gpu_count_;
 
   struct PlatformSpecific;
-  scoped_ptr<PlatformSpecific> platform_specific_;
 
   ObserverList<GpuSwitchingObserver> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuSwitchingManager);
 };
 
 }  // namespace ui
 
 #endif  // UI_GL_GPU_SWITCHING_MANAGER_H_