Move Singleton and related structs to namespace base

chrome/browser/extensions/api/desktop_capture/desktop_capture_base.cc

 // Copyright 2015 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/extensions/api/desktop_capture/desktop_capture_base.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/media/desktop_media_list_ash.h"
 #include "chrome/browser/media/desktop_streams_registry.h"
@@ skipping 196 matching lines @@
   DesktopCaptureRequestsRegistry::GetInstance()->CancelRequest(
       render_frame_host()->GetProcess()->GetID(), request_id);
   return true;
 }
 
 DesktopCaptureRequestsRegistry::DesktopCaptureRequestsRegistry() {}
 DesktopCaptureRequestsRegistry::~DesktopCaptureRequestsRegistry() {}
 
 // static
 DesktopCaptureRequestsRegistry* DesktopCaptureRequestsRegistry::GetInstance() {
-  return Singleton<DesktopCaptureRequestsRegistry>::get();
+  return base::Singleton<DesktopCaptureRequestsRegistry>::get();
 }
 
 void DesktopCaptureRequestsRegistry::AddRequest(
     int process_id,
     int request_id,
     DesktopCaptureChooseDesktopMediaFunctionBase* handler) {
   requests_.insert(
       RequestsMap::value_type(RequestId(process_id, request_id), handler));
 }
 
 void DesktopCaptureRequestsRegistry::RemoveRequest(int process_id,
                                                    int request_id) {
   requests_.erase(RequestId(process_id, request_id));
 }
 
 void DesktopCaptureRequestsRegistry::CancelRequest(int process_id,
                                                    int request_id) {
   RequestsMap::iterator it = requests_.find(RequestId(process_id, request_id));
   if (it != requests_.end())
     it->second->Cancel();
 }
 
 
 }  // namespace extensions