Move Singleton and related structs to namespace base

ui/events/gesture_detection/gesture_configuration_android.cc

Index: ui/events/gesture_detection/gesture_configuration_android.cc
diff --git a/ui/events/gesture_detection/gesture_configuration_android.cc b/ui/events/gesture_detection/gesture_configuration_android.cc
index 4fa2cff90e99d890c14295ba079128f28b9b6c18..54cb8c6798e3a514c871374690eff8f1704ce880 100644
--- a/ui/events/gesture_detection/gesture_configuration_android.cc
+++ b/ui/events/gesture_detection/gesture_configuration_android.cc
@@ -26,7 +26,7 @@ class GestureConfigurationAndroid : public GestureConfiguration {
   }
 
   static GestureConfigurationAndroid* GetInstance() {
-    return Singleton<GestureConfigurationAndroid>::get();
+    return base::Singleton<GestureConfigurationAndroid>::get();
   }
 
  private:
@@ -60,7 +60,7 @@ class GestureConfigurationAndroid : public GestureConfiguration {
         ViewConfiguration::GetLongPressTimeoutInMs());
   }
 
-  friend struct DefaultSingletonTraits<GestureConfigurationAndroid>;
+  friend struct base::DefaultSingletonTraits<GestureConfigurationAndroid>;
   DISALLOW_COPY_AND_ASSIGN(GestureConfigurationAndroid);
 };