Move Singleton and related structs to namespace base

Public APIs from base should live inside base:: so moved Singleton class
and structs to base{} and fixed consumers.

also fixed:

** Presubmit ERRORS **
Found Singleton<T> in the following header files.
Please move them to an appropriate source file so that the template
gets instantiated in a single compilation unit.
  chrome/browser/plugins/plugin_finder.h \
  chromecast/media/base/media_message_loop.h \
  content/browser/media/android/media_drm_credential_manager.h

Presubmit warnings:
src/chrome/browser/extensions/warning_badge_service_factory.h:5:
  #ifndef header guard has wrong style, please use:
  CHROME_BROWSER_EXTENSIONS_WARNING_BADGE_SERVICE_FACTORY_H_
  [build/header_guard] [5]
src/chrome/browser/extensions/warning_badge_service_factory.h:39:
  #endif line should be "#endif  //
  CHROME_BROWSER_EXTENSIONS_WARNING_BADGE_SERVICE_FACTORY_H_"
  [build/header_guard] [5]

TBR=jam@chromium.org

Review URL: https://codereview.chromium.org/1308823002

Cr-Commit-Position: refs/heads/master@{#348136}

2 files changed, 2 insertions, 2 deletions

diff --git a/extensions/browser/updater/update_service_factory.cc b/extensions/browser/updater/update_service_factory.cc
index a85cb06..a87c88b 100644
--- a/extensions/browser/updater/update_service_factory.cc
+++ b/extensions/browser/updater/update_service_factory.cc
@@ -20,7 +20,7 @@ UpdateService* UpdateServiceFactory::GetForBrowserContext(
 
 // static
 UpdateServiceFactory* UpdateServiceFactory::GetInstance() {
-  return Singleton<UpdateServiceFactory>::get();
+  return base::Singleton<UpdateServiceFactory>::get();
 }
 
 UpdateServiceFactory::UpdateServiceFactory()
diff --git a/extensions/browser/updater/update_service_factory.h b/extensions/browser/updater/update_service_factory.h
index 7b2726e..a31a668 100644
--- a/extensions/browser/updater/update_service_factory.h
+++ b/extensions/browser/updater/update_service_factory.h
@@ -20,7 +20,7 @@ class UpdateServiceFactory : public BrowserContextKeyedServiceFactory {
   static UpdateServiceFactory* GetInstance();
 
  private:
-  friend struct DefaultSingletonTraits<UpdateServiceFactory>;
+  friend struct base::DefaultSingletonTraits<UpdateServiceFactory>;
 
   UpdateServiceFactory();
   ~UpdateServiceFactory() override;