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

ash/wm/workspace/workspace_window_resizer.h

Index: ash/wm/workspace/workspace_window_resizer.h
diff --git a/ash/wm/workspace/workspace_window_resizer.h b/ash/wm/workspace/workspace_window_resizer.h
index 51e06ab9fcd5b1675b8b773576b5e03dae550855..f747b216dc4ce9f37ddebedd89c67d786e870490 100644
--- a/ash/wm/workspace/workspace_window_resizer.h
+++ b/ash/wm/workspace/workspace_window_resizer.h
@@ -52,6 +52,14 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
     return details_.initial_location_in_parent;
   }
 
+  PhantomWindowController* snap_phantom_window_controller_for_testing() const {
+    return snap_phantom_window_controller_.get();
+  }
+
+  PhantomWindowController* drag_phantom_window_controller_for_testing() const {
+    return drag_phantom_window_controller_.get();
+  }
+
   // Overridden from WindowResizer:
   virtual void Drag(const gfx::Point& location, int event_flags) OVERRIDE;
   virtual void CompleteDrag(int event_flags) OVERRIDE;
@@ -115,7 +123,7 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
                                int grid_size);
 
   // Updates the bounds of the phantom window for window dragging.
-  void UpdateDragPhantomWindow(const gfx::Rect& bounds);
+  void UpdateDragPhantomWindow(const gfx::Rect& bounds, bool in_original_root);
 
   // Restacks the windows z-order position so that one of the windows is at the
   // top of the z-order, and the rest directly underneath it.
@@ -165,9 +173,7 @@ class ASH_EXPORT WorkspaceWindowResizer : public WindowResizer {
   // is a grid and the caption is being dragged.
   scoped_ptr<PhantomWindowController> snap_phantom_window_controller_;
 
-  // For now, we show a phantom window on the other root window during dragging.
-  // TODO(yusukes): Show a semi-transparent image (screen shot) of the window
-  // instead.
+  // Shows a semi-transparent image of the window being dragged.
   scoped_ptr<PhantomWindowController> drag_phantom_window_controller_;
 
   // Used to determine the target position of a snap.