Move Singleton and related structs to namespace base

ui/gl/gpu_switching_manager.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 "ui/gl/gpu_switching_manager.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "ui/gl/gl_switches.h"
 
 #if defined(OS_MACOSX)
 #include <OpenGL/OpenGL.h>
 #include "base/mac/mac_util.h"
 #include "ui/gl/gl_context_cgl.h"
 #endif  // OS_MACOSX
 
 namespace ui {
 
 struct GpuSwitchingManager::PlatformSpecific {
 #if defined(OS_MACOSX)
   CGLPixelFormatObj discrete_pixel_format;
 #endif  // OS_MACOSX
 };
 
 // static
 GpuSwitchingManager* GpuSwitchingManager::GetInstance() {
-  return Singleton<GpuSwitchingManager>::get();
+  return base::Singleton<GpuSwitchingManager>::get();
 }
 
 GpuSwitchingManager::GpuSwitchingManager()
     : gpu_switching_option_(gfx::PreferIntegratedGpu),
       gpu_switching_option_set_(false),
       supports_dual_gpus_(false),
       supports_dual_gpus_set_(false),
       platform_specific_(new PlatformSpecific) {
 #if defined(OS_MACOSX)
   platform_specific_->discrete_pixel_format = nullptr;
@@ skipping 109 matching lines @@
     return;
   CGLPixelFormatAttribute attribs[1];
   attribs[0] = static_cast<CGLPixelFormatAttribute>(0);
   GLint num_pixel_formats = 0;
   CGLChoosePixelFormat(attribs, &platform_specific_->discrete_pixel_format,
                        &num_pixel_formats);
 }
 #endif  // OS_MACOSX
 
 }  // namespace ui