Promotes WmWindowMus functions to WmWindowAura and nukes WmWindowMus

ash/mus/move_event_handler.h

Index: ash/mus/move_event_handler.h
diff --git a/ash/mus/move_event_handler.h b/ash/mus/move_event_handler.h
index 531f37c0129fbc92ea1c15ea2bc9b9bca6109283..104b74eb5263d968cebbfd705d4fa644eb8f2ca4 100644
--- a/ash/mus/move_event_handler.h
+++ b/ash/mus/move_event_handler.h
@@ -22,9 +22,11 @@ class CancelModeEvent;
 }
 
 namespace ash {
+
+class WmWindowAura;
+
 namespace mus {
 
-class WmWindowMus;
 class WorkspaceEventHandlerMus;
 
 // EventHandler attached to windows that may be dragged and/or resized. This
@@ -73,7 +75,7 @@ class MoveEventHandler : public ui::EventHandler, public aura::WindowObserver {
   // Overridden from aura::WindowObserver:
   void OnWindowDestroying(aura::Window* window) override;
 
-  WmWindowMus* wm_window_;
+  ash::WmWindowAura* wm_window_;
   aura::WindowManagerClient* window_manager_client_;
   wm::WmToplevelWindowEventHandler toplevel_window_event_handler_;