Implement workspace scrubbing

ash/wm/workspace_controller.h

 // 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.
 
 #ifndef ASH_WM_WORKSPACE_CONTROLLER_H_
 #define ASH_WM_WORKSPACE_CONTROLLER_H_
 
 #include "ash/ash_export.h"
 #include "ash/wm/workspace/workspace_types.h"
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/aura/client/activation_change_observer.h"
 
 namespace aura {
 class Window;
 }
 
 namespace ash {
 namespace internal {
 
 class ShelfLayoutManager;
 class WorkspaceControllerTestHelper;
+class WorkspaceCycler;
 class WorkspaceEventHandler;
 class WorkspaceManager;
 
 // WorkspaceController acts as a central place that ties together all the
 // various workspace pieces.
 class ASH_EXPORT WorkspaceController
     : public aura::client::ActivationChangeObserver {
  public:
   explicit WorkspaceController(aura::Window* viewport);
   virtual ~WorkspaceController();
@@ skipping 16 matching lines @@
   virtual void OnWindowActivated(aura::Window* window,
                                  aura::Window* old_active) OVERRIDE;
 
  private:
   friend class WorkspaceControllerTestHelper;
 
   aura::Window* viewport_;
 
   scoped_ptr<WorkspaceManager> workspace_manager_;
 
+  // Cycles through the WorkspaceManager's workspaces in response to
+  // Ctrl-up-drag / Ctrl-down-drag.
+  scoped_ptr<WorkspaceCycler> workspace_cycler_;
+
   DISALLOW_COPY_AND_ASSIGN(WorkspaceController);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_WM_WORKSPACE_CONTROLLER_H_