Reland of [ash-md] Fades overview header in and out

ash/aura/wm_window_aura.h

Index: ash/aura/wm_window_aura.h
diff --git a/ash/aura/wm_window_aura.h b/ash/aura/wm_window_aura.h
index df281f12d3b000ae63a16e183a5f0dcd6ec8b238..66bfc6bdfa7dce7aaa6036ccae28bd10ba432999 100644
--- a/ash/aura/wm_window_aura.h
+++ b/ash/aura/wm_window_aura.h
@@ -74,10 +74,13 @@ class ASH_EXPORT WmWindowAura : public WmWindow,
   bool IsVisible() const override;
   void SetOpacity(float opacity) override;
   float GetTargetOpacity() const override;
+  gfx::Rect GetMinimizeAnimationTargetBoundsInScreen() const override;
   void SetTransform(const gfx::Transform& transform) override;
   gfx::Transform GetTargetTransform() const override;
   bool IsSystemModal() const override;
   bool GetBoolProperty(WmWindowProperty key) override;
+  SkColor GetColorProperty(WmWindowProperty key) override;
+  void SetColorProperty(WmWindowProperty key, SkColor value) override;
   int GetIntProperty(WmWindowProperty key) override;
   void SetIntProperty(WmWindowProperty key, int value) override;
   ShelfItemDetails* GetShelfItemDetails() override;