gn/linux: warnings as errors, turn on Wextra

ash/shelf/shelf_view.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 ASH_SHELF_SHELF_VIEW_H_
 #define ASH_SHELF_SHELF_VIEW_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 115 matching lines @@
   virtual void UpdateDragIconProxy(
       const gfx::Point& location_in_screen_coordinates) OVERRIDE;
   virtual void DestroyDragIconProxy() OVERRIDE;
   virtual bool StartDrag(
       const std::string& app_id,
       const gfx::Point& location_in_screen_coordinates) OVERRIDE;
   virtual bool Drag(const gfx::Point& location_in_screen_coordinates) OVERRIDE;
   virtual void EndDrag(bool cancel) OVERRIDE;
 
   // Return the view model for test purposes.
-  const views::ViewModel* const view_model_for_test() const {
+  const views::ViewModel* view_model_for_test() const {
     return view_model_.get();
   }
 
  private:
   friend class ash::test::ShelfViewTestAPI;
 
   class FadeOutAnimationDelegate;
   class StartFadeAnimationDelegate;
 
   struct IdealBounds {
@@ skipping 292 matching lines @@
 
   // True when ripped item from overflow bubble is entered into Shelf.
   bool dragged_off_from_overflow_to_shelf_;
 
   DISALLOW_COPY_AND_ASSIGN(ShelfView);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELF_SHELF_VIEW_H_