Wires up immersive mode for chrome and mash

ash/mus/frame/detached_title_area_renderer_host.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_MUS_FRAME_DETATCHED_TITLE_AREA_RENDERER_HOST_H_
+#define ASH_MUS_FRAME_DETATCHED_TITLE_AREA_RENDERER_HOST_H_
+
+namespace ash {
+namespace mus {
+
+class DetachedTitleAreaRenderer;
+
+// Used to inform the creator of DetachedTitleAreaRenderer of interesting
+// events.
+class DetachedTitleAreaRendererHost {
+ public:
+  virtual void OnDetachedTitleAreaRendererDestroyed(
+      DetachedTitleAreaRenderer* renderer) = 0;
+
+ protected:
+  virtual ~DetachedTitleAreaRendererHost() {}
+};
+
+}  // namespace mus
+}  // namespace ash
+
+#endif  // ASH_MUS_FRAME_DETATCHED_TITLE_AREA_RENDERER_HOST_H_