Move Singleton and related structs to namespace base

content/browser/accessibility/browser_accessibility_state_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_STATE_IMPL_H_
 #define CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_STATE_IMPL_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 56 matching lines @@
   // in a test.
   void set_disable_hot_tracking_for_testing(bool disable_hot_tracking) {
     disable_hot_tracking_ = disable_hot_tracking;
   }
   bool disable_hot_tracking_for_testing() const {
     return disable_hot_tracking_;
   }
 
  private:
   friend class base::RefCountedThreadSafe<BrowserAccessibilityStateImpl>;
-  friend struct DefaultSingletonTraits<BrowserAccessibilityStateImpl>;
+  friend struct base::DefaultSingletonTraits<BrowserAccessibilityStateImpl>;
 
   // Resets accessibility_mode_ to the default value.
   void ResetAccessibilityModeValue();
 
   // Called a short while after startup to allow time for the accessibility
   // state to be determined. Updates histograms with the current state.
   void UpdateHistograms();
 
   // Leaky singleton, destructor generally won't be called.
   ~BrowserAccessibilityStateImpl() override;
 
   void UpdatePlatformSpecificHistograms();
 
   // Updates the accessibility mode of all web contents, including swapped out
   // ones. |add| specifies whether the mode should be added or removed.
   void AddOrRemoveFromAllWebContents(AccessibilityMode mode, bool add);
 
   AccessibilityMode accessibility_mode_;
 
   std::vector<base::Closure> histogram_callbacks_;
 
   bool disable_hot_tracking_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityStateImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_STATE_IMPL_H_