ui: Fix clang warnings about missing virtual and OVERRIDE annotations.

ui/base/dragdrop/drag_utils.cc

 // 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.
 
 #include "ui/base/dragdrop/drag_utils.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
 #include "googleurl/src/gurl.h"
@@ skipping 21 matching lines @@
   FileDragImageSource(const FilePath& file_name, const gfx::ImageSkia& icon)
       : CanvasImageSource(CalculateSize(icon), false),
         file_name_(file_name),
         icon_(icon) {
   }
 
   virtual ~FileDragImageSource() {
   }
 
   // Overridden from gfx::CanvasImageSource.
-  void Draw(gfx::Canvas* canvas) OVERRIDE {
+  virtual void Draw(gfx::Canvas* canvas) OVERRIDE {
     // Set up our text portion
     ResourceBundle& rb = ResourceBundle::GetSharedInstance();
     gfx::Font font = rb.GetFont(ResourceBundle::BaseFont);
 
     // Paint the icon.
     canvas->DrawImageInt(icon_, (size().width() - icon_.width()) / 2, 0);
 
     string16 name = file_name_.BaseName().LossyDisplayName();
     const int flags = gfx::Canvas::TEXT_ALIGN_CENTER;
 #if defined(OS_WIN)
@@ skipping 47 matching lines @@
 
 void SetDragImageOnDataObject(const gfx::Canvas& canvas,
                               const gfx::Size& size,
                               const gfx::Point& cursor_offset,
                               ui::OSExchangeData* data_object) {
   gfx::ImageSkia image = gfx::ImageSkia(canvas.ExtractImageRep());
   SetDragImageOnDataObject(image, size, cursor_offset, data_object);
 }
 
 }  // namespace drag_utils