Implement workspace scrubbing

ash/wm/workspace/workspace.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_WORKSPACE_H_
 #define ASH_WM_WORKSPACE_WORKSPACE_H_
 
 #include <vector>
 
 #include "ash/ash_export.h"
@@ skipping 37 matching lines @@
   }
   WorkspaceLayoutManager* workspace_layout_manager() {
     return workspace_layout_manager_;
   }
 
   const WorkspaceManager* workspace_manager() const {
     return workspace_manager_;
   }
   WorkspaceManager* workspace_manager() { return workspace_manager_; }
 
+  // Returns the active window if the active window is in this workspace.
+  // Otherwise, NULL is returned.
+  aura::Window* GetActiveWindow() const;
+
   // Returns true if the Workspace should be moved to pending. This is true
   // if there are no visible maximized windows.
   bool ShouldMoveToPending() const;
 
   // Returns the number of maximized windows (including minimized windows that
   // would be maximized on restore). This does not consider visibility.
   int GetNumMaximizedWindows() const;
 
  private:
   // Is this a workspace for maximized windows?
   const bool is_maximized_;
 
   WorkspaceManager* workspace_manager_;
 
   // Our Window, owned by |parent| passed to the constructor.
   aura::Window* window_;
 
   scoped_ptr<WorkspaceEventHandler> event_handler_;
 
   WorkspaceLayoutManager* workspace_layout_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(Workspace);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_WM_WORKSPACE_WORKSPACE_H_