Draw web content area correctly on a phantom window for window dragging

ash/wm/workspace/phantom_window_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_WM_WORKSPACE_PHANTOM_WINDOW_CONTROLLER_H_
 #define ASH_WM_WORKSPACE_PHANTOM_WINDOW_CONTROLLER_H_
 
 #include "ash/ash_export.h"
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/base/animation/animation_delegate.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/rect.h"
 
 namespace aura {
+class RootWindow;
 class Window;
-class RootWindow;
 }
 
 namespace ui {
+class Layer;
 class SlideAnimation;
 }
 
 namespace views {
 class Widget;
 }
 
 namespace ash {
 namespace internal {
 
 // PhantomWindowController is responsible for showing a phantom representation
 // of a window. It's used used during dragging a window to show a snap location.
 class ASH_EXPORT PhantomWindowController : public ui::AnimationDelegate {
  public:
+  // TODO(yusukes): Rename STYLE_WINDOW to STYLE_NONE and remove WindowPainter.
+  // See comments in CreatePhantomWidget() for more details.
   enum Style {
     STYLE_SHADOW,  // for window snapping.
     STYLE_WINDOW,  // for window dragging.
   };
 
   explicit PhantomWindowController(aura::Window* window);
   virtual ~PhantomWindowController();
 
   // Sets the display where the phantom is placed.
   void SetDestinationDisplay(const gfx::Display& dst_display);
@@ skipping 14 matching lines @@
 
   // Returns true if the phantom is showing.
   bool IsShowing() const;
 
   // If set, the phantom window is stacked below this window, otherwise it
   // is stacked above the window passed to the constructor.
   void set_phantom_below_window(aura::Window* phantom_below_window) {
     phantom_below_window_ = phantom_below_window;
   }
 
+  // Sets/gets the |layer| which is shown on top of the |phantom_widget_|.
+  // PhantomWindowController does not own the |layer|.
+  void set_layer(ui::Layer* layer);
+  ui::Layer* layer() const { return layer_; }
+
   // Sets/gets the style of the phantom window.
   void set_style(Style style);
   Style style() const { return style_; }
 
   // Sets/gets the opacity of the phantom window.
   void SetOpacity(float opacity);
   float GetOpacity() const;
 
   // ui::AnimationDelegate overrides:
   virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
@@ skipping 25 matching lines @@
   gfx::Rect bounds_;
 
   views::Widget* phantom_widget_;
 
   // Used to transition the bounds.
   scoped_ptr<ui::SlideAnimation> animation_;
 
   // The style of the phantom window.
   Style style_;
 
+  // The layer which should be shown on top of the |phantom_widget_|. NULL when
+  // no layer needs to be shown. This object does not own the layer.
+  ui::Layer* layer_;
+
   DISALLOW_COPY_AND_ASSIGN(PhantomWindowController);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_WM_WORKSPACE_PHANTOM_WINDOW_CONTROLLER_H_