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}

1 files changed, 4 insertions, 3 deletions

diff --git a/chromeos/system/statistics_provider.cc b/chromeos/system/statistics_provider.cc
index bac7173..c2cfcdb 100644
--- a/chromeos/system/statistics_provider.cc
+++ b/chromeos/system/statistics_provider.cc
@@ -113,7 +113,7 @@ class StatisticsProviderImpl : public StatisticsProvider {
 
  protected:
   typedef std::map<std::string, bool> MachineFlags;
-  friend struct DefaultSingletonTraits<StatisticsProviderImpl>;
+  friend struct base::DefaultSingletonTraits<StatisticsProviderImpl>;
 
   StatisticsProviderImpl();
   ~StatisticsProviderImpl() override;
@@ -342,8 +342,9 @@ void StatisticsProviderImpl::LoadOemManifestFromFile(
 }
 
 StatisticsProviderImpl* StatisticsProviderImpl::GetInstance() {
-  return Singleton<StatisticsProviderImpl,
-                   DefaultSingletonTraits<StatisticsProviderImpl> >::get();
+  return base::Singleton<
+      StatisticsProviderImpl,
+      base::DefaultSingletonTraits<StatisticsProviderImpl>>::get();
 }
 
 static StatisticsProvider* g_test_statistics_provider = NULL;