mash: Partially migrate WorkspaceController to ash common.

ash/common/wm/wm_window_animations.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ASH_COMMON_WM_WM_WINDOW_ANIMATIONS_H_
+#define ASH_COMMON_WM_WM_WINDOW_ANIMATIONS_H_
+
+#include "ash/ash_export.h"
+
+namespace ui {
+class Layer;
+}
+
+// This is only for animations specific to Ash. For window animations shared
+// with desktop Chrome, see ui/views/corewm/window_animations.h.
+namespace ash {
+
+// Direction for ash-specific window animations used in workspaces and
+// lock/unlock animations.
+enum LayerScaleAnimationDirection {
+  LAYER_SCALE_ANIMATION_ABOVE,
+  LAYER_SCALE_ANIMATION_BELOW,
+};
+
+// Applies scale related to the specified AshWindowScaleType.
+ASH_EXPORT void SetTransformForScaleAnimation(
+    ui::Layer* layer,
+    LayerScaleAnimationDirection type);
+
+}  // namespace ash
+
+#endif  // ASH_COMMON_WM_WM_WINDOW_ANIMATIONS_H_