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

ash/wm/window_util.h

Index: ash/wm/window_util.h
diff --git a/ash/wm/window_util.h b/ash/wm/window_util.h
index 6dc9d2a2aa4d5c0137072744fb6a6f5010106d82..e994f4d40a5fb8f01655b5d608bcf0fd4383acc7 100644
--- a/ash/wm/window_util.h
+++ b/ash/wm/window_util.h
@@ -12,6 +12,10 @@ class RootWindow;
 class Window;
 }
 
+namespace ui {
+class Layer;
+}
+
 namespace ash {
 namespace internal {
 class RootWindowController;
@@ -56,6 +60,14 @@ ASH_EXPORT void RestoreWindow(aura::Window* window);
 // Moves the window to the center of the display.
 ASH_EXPORT void CenterWindow(aura::Window* window);
 
+// Recreates a fresh layer for |window| and all its child windows. Does not
+// recreate shadows or other non-window layers. Returns the old layer and its
+// children, maintaining the hierarchy.
+ASH_EXPORT ui::Layer* RecreateWindowLayers(aura::Window* window);
+
+// Deletes |layer| and all its child layers.
+ASH_EXPORT void DeepDeleteLayers(ui::Layer* layer);
+
 }  // namespace wm
 }  // namespace ash