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/chrome/browser/task_manager/task_manager.cc b/chrome/browser/task_manager/task_manager.cc
index b46c6f5..f89ad83 100644
--- a/chrome/browser/task_manager/task_manager.cc
+++ b/chrome/browser/task_manager/task_manager.cc
@@ -1548,7 +1548,7 @@ void TaskManager::ModelChanged() {
 
 // static
 TaskManager* TaskManager::GetInstance() {
-  return Singleton<TaskManager>::get();
+  return base::Singleton<TaskManager>::get();
 }
 
 void TaskManager::OpenAboutMemory(chrome::HostDesktopType desktop_type) {
diff --git a/chrome/browser/task_manager/task_manager.h b/chrome/browser/task_manager/task_manager.h
index 13299b6..4ed4f0c 100644
--- a/chrome/browser/task_manager/task_manager.h
+++ b/chrome/browser/task_manager/task_manager.h
@@ -99,7 +99,7 @@ class TaskManager {
 
   // Obtain an instance via GetInstance().
   TaskManager();
-  friend struct DefaultSingletonTraits<TaskManager>;
+  friend struct base::DefaultSingletonTraits<TaskManager>;
 
   ~TaskManager();