Wires up immersive mode for chrome and mash

ash/mus/frame/detached_title_area_renderer.h

Index: ash/mus/frame/detached_title_area_renderer.h
diff --git a/ash/mus/frame/detached_title_area_renderer.h b/ash/mus/frame/detached_title_area_renderer.h
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+// 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_DETACHED_TITLE_AREA_RENDERER_H_
+#define ASH_MUS_FRAME_DETACHED_TITLE_AREA_RENDERER_H_
+
+#include "base/macros.h"
+#include "ui/views/widget/widget_delegate.h"
+
+namespace ui {
+class Window;
+}
+
+namespace ash {
+namespace mus {
+
+class DetachedTitleAreaRendererHost;
+
+// DetachedTitleAreaRenderer contains a HeaderView in a widget. It's intended to
+// be used when the title area needs to be rendered in a window different from
+// the normal window the title area renders to (such as in immersive mode).
+class DetachedTitleAreaRenderer : public views::WidgetDelegate {
+ public:
+  // Used to indicate why this is being created.
+  enum class Source {
+    // This is being created at the request of a client, specifically because
+    // of kRendererParentTitleArea_Property set on a client owned window.
+    CLIENT,
+
+    // Mash is creating this class to host an immersive reveal. Note that CLIENT
+    // is also likely used for an immersive reveal, but for CLIENT the client
+    // is completely controlling the reveal and not mash. In other words for
+    // CLIENT ImmersiveFullscreenController is not running in mash.
+    MASH,
+  };
+
+  // Creates a widget to render the title area and shows it. |window| is the
+  // window to render to and |widget| the widget whose frame state is rendered
+  // to |window|. This object is deleted either when |window| is destroyed, or
+  // Destroy() is called.
+  DetachedTitleAreaRenderer(DetachedTitleAreaRendererHost* host,
+                            views::Widget* frame,
+                            ui::Window* window,
+                            Source source);
+
+  void Destroy();
+
+  views::Widget* widget() { return widget_; }
+
+  // views::WidgetDelegate:
+  views::Widget* GetWidget() override;
+  const views::Widget* GetWidget() const override;
+  void DeleteDelegate() override;
+
+ private:
+  ~DetachedTitleAreaRenderer() override;
+
+  DetachedTitleAreaRendererHost* host_;
+  views::Widget* frame_;
+  views::Widget* widget_;
+
+  DISALLOW_COPY_AND_ASSIGN(DetachedTitleAreaRenderer);
+};
+
+}  // namespace mus
+}  // namespace ash
+
+#endif  // ASH_MUS_FRAME_DETACHED_TITLE_AREA_RENDERER_H_