MacViews: Put wm window animation calls behind an interface.

ui/views/widget/desktop_aura/desktop_native_widget_aura.h

Index: ui/views/widget/desktop_aura/desktop_native_widget_aura.h
diff --git a/ui/views/widget/desktop_aura/desktop_native_widget_aura.h b/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
index 1400235d3aae60d8493059c45a19a783aa0ecaaf..64c95d3bb0e1719be68c1b9ee3912766ba61fb07 100644
--- a/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
+++ b/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
@@ -173,6 +173,7 @@ class VIEWS_EXPORT DesktopNativeWidgetAura
       Widget::MoveLoopEscapeBehavior escape_behavior) override;
   void EndMoveLoop() override;
   void SetVisibilityChangedAnimationsEnabled(bool value) override;
+  Widget::VisibilityAnimation* GetVisibilityAnimation() const override;
   ui::NativeTheme* GetNativeTheme() const override;
   void OnRootViewLayout() override;
   bool IsTranslucentWindowOpacitySupported() const override;
@@ -308,6 +309,8 @@ class VIEWS_EXPORT DesktopNativeWidgetAura
   // See class documentation for Widget in widget.h for a note about type.
   Widget::InitParams::Type widget_type_;
 
+  scoped_ptr<Widget::VisibilityAnimation> visibility_animation_;
+
   // The following factory is used for calls to close the NativeWidgetAura
   // instance.
   base::WeakPtrFactory<DesktopNativeWidgetAura> close_widget_factory_;