cros: Change look of partial magnifier.

ash/magnifier/partial_magnification_controller.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_MAGNIFIER_PARTIAL_MAGNIFICATION_CONTROLLER_H_
 #define ASH_MAGNIFIER_PARTIAL_MAGNIFICATION_CONTROLLER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
@@ skipping 68 matching lines @@
 
   // The host widget is the root parent for all of the layers. The widget's
   // location follows the mouse, which causes the layers to also move.
   views::Widget* host_widget_ = nullptr;
 
   // Draws the background with a zoom filter applied.
   std::unique_ptr<ui::Layer> zoom_layer_;
   // Draws an outline that is overlayed on top of |zoom_layer_|.
   std::unique_ptr<ui::Layer> border_layer_;
   // Draws a multicolored black/white/black border on top of |border_layer_|.
-  // This must be ordered after |border_layer_| so that it gets destroyed after
-  // |border_layer_|, otherwise |border_layer_| will have a pointer to a deleted
-  // delegate.
+  // Also draws a shadow around the border. This must be ordered after
+  // |border_layer_| so that it gets destroyed after |border_layer_|, otherwise
+  // |border_layer_| will have a pointer to a deleted delegate.
   std::unique_ptr<BorderRenderer> border_renderer_;
   // Masks the content of |zoom_layer_| so that only a circle is magnified.
   std::unique_ptr<ContentMask> zoom_mask_;
   // Masks the content of |border_layer_| so that only a circle outline is
   // drawn.
   std::unique_ptr<ContentMask> border_mask_;
 
   DISALLOW_COPY_AND_ASSIGN(PartialMagnificationController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_MAGNIFIER_PARTIAL_MAGNIFICATION_CONTROLLER_H_