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

ash/wm/workspace_controller.cc

 // 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.
 
 #include "ash/wm/workspace_controller.h"
 
 #include "ash/wm/window_util.h"
 #include "ash/wm/workspace/workspace_manager.h"
 #include "ui/aura/client/activation_client.h"
 #include "ui/aura/client/aura_constants.h"
@@ skipping 24 matching lines @@
 }
 
 void WorkspaceController::SetActiveWorkspaceByWindow(aura::Window* window) {
   return workspace_manager_->SetActiveWorkspaceByWindow(window);
 }
 
 aura::Window* WorkspaceController::GetActiveWorkspaceWindow() {
   return workspace_manager_->GetActiveWorkspaceWindow();
 }
 
+WorkspaceEventHandler* WorkspaceController::GetEventHandlerForWindow(
+    aura::Window* window) {
+  return workspace_manager_->GetEventHandlerForWindow(window);
+}
+
 aura::Window* WorkspaceController::GetParentForNewWindow(aura::Window* window) {
   return workspace_manager_->GetParentForNewWindow(window);
 }
 
 void WorkspaceController::DoInitialAnimation() {
   workspace_manager_->DoInitialAnimation();
 }
 
 void WorkspaceController::OnWindowActivated(aura::Window* gained_active,
                                             aura::Window* lost_active) {
   if (!gained_active ||
       gained_active->GetRootWindow() == viewport_->GetRootWindow()) {
     workspace_manager_->SetActiveWorkspaceByWindow(gained_active);
   }
 }
 
 }  // namespace internal
 }  // namespace ash