Attach panel while dragging to bring it in front of other panels.

ash/wm/workspace/workspace_window_resizer.cc

Index: ash/wm/workspace/workspace_window_resizer.cc
diff --git a/ash/wm/workspace/workspace_window_resizer.cc b/ash/wm/workspace/workspace_window_resizer.cc
index 6c23c9f16afc801f8cdaa67c6aae74ac19316551..44096ad9f740ef6825d34751888d7aac1f96a8ea 100644
--- a/ash/wm/workspace/workspace_window_resizer.cc
+++ b/ash/wm/workspace/workspace_window_resizer.cc
@@ -33,7 +33,8 @@
 
 namespace ash {
 
-scoped_ptr<WindowResizer> CreateWindowResizer(aura::Window* window,
+scoped_ptr<WindowResizer> CreateWindowResizer(WindowResizerOwner* owner,
+                                              aura::Window* window,
                                               const gfx::Point& point_in_parent,
                                               int window_component) {
   DCHECK(window);
@@ -44,7 +45,7 @@ scoped_ptr<WindowResizer> CreateWindowResizer(aura::Window* window,
   WindowResizer* window_resizer = NULL;
   if (window->type() == aura::client::WINDOW_TYPE_PANEL) {
     window_resizer = PanelWindowResizer::Create(
-        window, point_in_parent, window_component);
+        owner, window, point_in_parent, window_component);
   } else if (window->parent() &&
       window->parent()->id() == internal::kShellWindowId_WorkspaceContainer) {
     // Allow dragging maximized windows if it's not tracked by workspace. This