Move the concept of Activation to the Shell.

ui/aura_shell/default_container_event_filter.cc

 // Copyright (c) 2011 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 "ui/aura_shell/default_container_event_filter.h"
 
 #include "ui/aura/event.h"
 #include "ui/aura/window.h"
 #include "ui/aura_shell/default_container_layout_manager.h"
-#include "ui/aura_shell/stacking_controller.h"
 #include "ui/aura_shell/window_frame.h"
+#include "ui/aura_shell/window_util.h"
 #include "ui/base/hit_test.h"
 
 namespace {
 
 // Sends OnWindowHoveredChanged(|hovered|) to the WindowFrame for |window|,
 // which may be NULL.
 void WindowHoverChanged(aura::Window* window, bool hovered) {
   if (!window)
     return;
   aura_shell::WindowFrame* window_frame =
@@ skipping 48 matching lines @@
             layout_manager->ProcessMove(target, event);
             break;
           case DRAG_RESIZE:
             break;
         }
       } else {
         layout_manager->CancelMoveOrResize(target, event);
       }
       break;
     case ui::ET_MOUSE_ENTERED:
-      UpdateHoveredWindow(StackingController::GetActivatableWindow(target));
+      UpdateHoveredWindow(GetActivatableWindow(target));
       break;
     case ui::ET_MOUSE_EXITED:
       UpdateHoveredWindow(NULL);
       break;
     case ui::ET_MOUSE_RELEASED:
       if (drag_state_ == DRAG_MOVE)
         layout_manager->EndMove(target, event);
       else if (drag_state_ == DRAG_RESIZE)
         layout_manager->EndResize(target, event);
 
@@ skipping 32 matching lines @@
     aura::Window* toplevel_window) {
   if (toplevel_window == hovered_window_)
     return;
   WindowHoverChanged(hovered_window_, false);
   hovered_window_ = toplevel_window;
   WindowHoverChanged(hovered_window_, true);
 }
 
 }  // internal
 }  // aura_shell