[mus+ash] Removes WmWindow from ash/wm/overview and ash/wm/workspace

ash/wm/workspace/workspace_event_handler_aura.h

Index: ash/wm/workspace/workspace_event_handler_aura.h
diff --git a/ash/wm/workspace/workspace_event_handler_aura.h b/ash/wm/workspace/workspace_event_handler_aura.h
index 86f163d5b8b96ef0ffa222a9a77b131b8ce0316e..62158703b1c6185f97c3314b1733b9cb6b971c51 100644
--- a/ash/wm/workspace/workspace_event_handler_aura.h
+++ b/ash/wm/workspace/workspace_event_handler_aura.h
@@ -10,14 +10,16 @@
 #include "base/macros.h"
 #include "ui/events/event_handler.h"
 
-namespace ash {
+namespace aura {
+class Window;
+}
 
-class WmWindow;
+namespace ash {
 
 class ASH_EXPORT WorkspaceEventHandlerAura : public ui::EventHandler,
                                              public WorkspaceEventHandler {
  public:
-  explicit WorkspaceEventHandlerAura(WmWindow* workspace_window);
+  explicit WorkspaceEventHandlerAura(aura::Window* workspace_window);
   ~WorkspaceEventHandlerAura() override;
 
   // ui::EventHandler:
@@ -25,7 +27,7 @@ class ASH_EXPORT WorkspaceEventHandlerAura : public ui::EventHandler,
   void OnGestureEvent(ui::GestureEvent* event) override;
 
  private:
-  WmWindow* workspace_window_;
+  aura::Window* workspace_window_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkspaceEventHandlerAura);
 };