mash: Partially migrate WorkspaceController to ash common.

ash/wm/workspace_controller.h

Index: ash/wm/workspace_controller.h
diff --git a/ash/wm/workspace_controller.h b/ash/wm/workspace_controller.h
index fb8e3c3f13c4a0b150cc9809b93e475147900185..610a65f842f6a9379e26f54dc4f5b4da7376aeea 100644
--- a/ash/wm/workspace_controller.h
+++ b/ash/wm/workspace_controller.h
@@ -11,12 +11,8 @@
 #include "ash/common/wm/workspace/workspace_types.h"
 #include "base/macros.h"
 
-namespace aura {
-class Window;
-}
-
 namespace ash {
-class ShelfLayoutManager;
+class WmWindow;
 class WorkspaceControllerTestHelper;
 class WorkspaceEventHandler;
 class WorkspaceLayoutManager;
@@ -26,14 +22,12 @@ class WorkspaceLayoutManagerBackdropDelegate;
 // various workspace pieces.
 class ASH_EXPORT WorkspaceController {
  public:
-  explicit WorkspaceController(aura::Window* viewport);
+  explicit WorkspaceController(WmWindow* viewport);
   virtual ~WorkspaceController();
 
   // Returns the current window state.
   wm::WorkspaceWindowState GetWindowState() const;
 
-  void SetShelf(ShelfLayoutManager* shelf);
-
   // Starts the animation that occurs on first login.
   void DoInitialAnimation();
 
@@ -47,9 +41,7 @@ class ASH_EXPORT WorkspaceController {
  private:
   friend class WorkspaceControllerTestHelper;
 
-  aura::Window* viewport_;
-
-  ShelfLayoutManager* shelf_;
+  WmWindow* viewport_;
   std::unique_ptr<WorkspaceEventHandler> event_handler_;
 
   // Owned by |viewport_|.