While dragging a window, show a semi-transparent aura window instead of the standard gray phantom wi

ash/wm/window_resizer.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_WM_WINDOW_RESIZER_H_
 #define ASH_WM_WINDOW_RESIZER_H_
 
 #include "ash/ash_export.h"
 #include "base/basictypes.h"
 #include "ui/gfx/rect.h"
@@ skipping 56 matching lines @@
 
     // The window we're resizing.
     aura::Window* window;
 
     // Initial bounds of the window.
     gfx::Rect initial_bounds;
 
     // Location passed to the constructor, in |window->parent()|'s coordinates.
     gfx::Point initial_location_in_parent;
 
+    // Initial opacity of the window.
+    float initial_opacity;
+
     // The component the user pressed on.
     int window_component;
 
     // Bitmask of the |kBoundsChange_| constants.
     int bounds_change;
 
     // Bitmask of the |kBoundsChangeDirection_| constants.
     int position_change_direction;
 
     // Bitmask of the |kBoundsChangeDirection_| constants.
@@ skipping 35 matching lines @@
   // Returns the height of the drag.
   static int GetHeightForDrag(const Details& details,
                               int min_height,
                               int* delta_y,
                               int grid_size);
 };
 
 }  // namespace aura
 
 #endif  // ASH_WM_WINDOW_RESIZER_H_