Move Singleton and related structs to namespace base

components/devtools_discovery/devtools_discovery_manager.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 "components/devtools_discovery/devtools_discovery_manager.h"
 
 #include "base/stl_util.h"
 #include "components/devtools_discovery/basic_target_descriptor.h"
 #include "content/public/browser/devtools_agent_host.h"
 
 using content::DevToolsAgentHost;
 
 namespace devtools_discovery {
 
 // static
 DevToolsDiscoveryManager* DevToolsDiscoveryManager::GetInstance() {
-  return Singleton<DevToolsDiscoveryManager>::get();
+  return base::Singleton<DevToolsDiscoveryManager>::get();
 }
 
 DevToolsDiscoveryManager::DevToolsDiscoveryManager() {
 }
 
 DevToolsDiscoveryManager::~DevToolsDiscoveryManager() {
   STLDeleteElements(&providers_);
 }
 
 void DevToolsDiscoveryManager::AddProvider(scoped_ptr<Provider> provider) {
@@ skipping 28 matching lines @@
 DevToolsDiscoveryManager::GetDescriptorsFromProviders() {
   DevToolsTargetDescriptor::List result;
   for (const auto& provider : providers_) {
     DevToolsTargetDescriptor::List partial = provider->GetDescriptors();
     result.insert(result.begin(), partial.begin(), partial.end());
   }
   return result;
 }
 
 }  // namespace devtools_discovery