Add OVERRIDE to content/.

content/browser/renderer_host/backing_store_gtk.h

Index: content/browser/renderer_host/backing_store_gtk.h
diff --git a/content/browser/renderer_host/backing_store_gtk.h b/content/browser/renderer_host/backing_store_gtk.h
index eeeb771b584415bc6c9f185693380c24a42e9cd9..b69862e2e07bed37a1b5eaa72929b1474b9dbf9f 100644
--- a/content/browser/renderer_host/backing_store_gtk.h
+++ b/content/browser/renderer_host/backing_store_gtk.h
@@ -56,19 +56,19 @@ class CONTENT_EXPORT BackingStoreGtk : public BackingStore {
 #endif
 
   // BackingStore implementation.
-  virtual size_t MemorySize();
+  virtual size_t MemorySize() OVERRIDE;
   virtual void PaintToBackingStore(
       RenderProcessHost* process,
       TransportDIB::Id bitmap,
       const gfx::Rect& bitmap_rect,
       const std::vector<gfx::Rect>& copy_rects,
       const base::Closure& completion_callback,
-      bool* scheduled_completion_callback);
+      bool* scheduled_completion_callback) OVERRIDE;
   virtual bool CopyFromBackingStore(const gfx::Rect& rect,
-                                    skia::PlatformCanvas* output);
+                                    skia::PlatformCanvas* output) OVERRIDE;
   virtual void ScrollBackingStore(int dx, int dy,
                                   const gfx::Rect& clip_rect,
-                                  const gfx::Size& view_size);
+                                  const gfx::Size& view_size) OVERRIDE;
 
  private:
   // Paints the bitmap from the renderer onto the backing store without