Move Singleton and related structs to namespace base

content/common/font_cache_dispatcher_win.cc

Index: content/common/font_cache_dispatcher_win.cc
diff --git a/content/common/font_cache_dispatcher_win.cc b/content/common/font_cache_dispatcher_win.cc
index e7d9eff5326025da69d0849fc838712a4dddc206..49ff631672a61b310b30a6406f4b8275531ca91b 100644
--- a/content/common/font_cache_dispatcher_win.cc
+++ b/content/common/font_cache_dispatcher_win.cc
@@ -19,9 +19,7 @@ typedef std::map<FontCacheDispatcher*, FontNameVector> DispatcherToFontNames;
 
 class FontCache {
  public:
-  static FontCache* GetInstance() {
-    return Singleton<FontCache>::get();
-  }
+  static FontCache* GetInstance() { return base::Singleton<FontCache>::get(); }
 
   void PreCacheFont(const LOGFONT& font, FontCacheDispatcher* dispatcher) {
     // TODO(ananta): Remove ScopedTracker below once crbug.com/90127 is fixed.
@@ -123,7 +121,7 @@ class FontCache {
     HDC dc_;
     int ref_count_;
   };
-  friend struct DefaultSingletonTraits<FontCache>;
+  friend struct base::DefaultSingletonTraits<FontCache>;
 
   FontCache() {
   }