Promotes remaining global window manager state into WindowManagerState

components/mus/ws/window_manager_display_root.h

Index: components/mus/ws/window_manager_display_root.h
diff --git a/components/mus/ws/window_manager_display_root.h b/components/mus/ws/window_manager_display_root.h
new file mode 100644
index 0000000000000000000000000000000000000000..94eda7372016556bc5cc157f93e2434767e898d0
--- /dev/null
+++ b/components/mus/ws/window_manager_display_root.h
@@ -0,0 +1,62 @@
+// 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 COMPONENTS_MUS_WS_WINDOW_MANAGER_DISPLAY_ROOT_H_
+#define COMPONENTS_MUS_WS_WINDOW_MANAGER_DISPLAY_ROOT_H_
+
+#include <stdint.h>
+
+#include <memory>
+
+#include "base/macros.h"
+
+namespace mus {
+namespace ws {
+
+class Display;
+class ServerWindow;
+class WindowManagerState;
+class WindowServer;
+
+namespace test {
+class WindowManagerDisplayRootTestApi;
+}
+
+// Owns the root window of a window manager for one display. Each window manager
+// has one WindowManagerDisplayRoot for each Display. The root window is
+// parented to the root of a Display.
+class WindowManagerDisplayRoot {
+ public:
+  explicit WindowManagerDisplayRoot(Display* display);
+  ~WindowManagerDisplayRoot();
+
+  ServerWindow* root() { return root_.get(); }
+  const ServerWindow* root() const { return root_.get(); }
+
+  Display* display() { return display_; }
+  const Display* display() const { return display_; }
+
+  WindowManagerState* window_manager_state() { return window_manager_state_; }
+  const WindowManagerState* window_manager_state() const {
+    return window_manager_state_;
+  }
+
+ private:
+  friend class Display;
+
+  WindowServer* window_server();
+
+  Display* display_;
+  // Root ServerWindow of this WindowManagerDisplayRoot. |root_| has a parent,
+  // the root ServerWindow of the Display.
+  std::unique_ptr<ServerWindow> root_;
+  WindowManagerState* window_manager_state_ = nullptr;
+
+  DISALLOW_COPY_AND_ASSIGN(WindowManagerDisplayRoot);
+};
+
+}  // namespace ws
+}  // namespace mus
+
+#endif  // COMPONENTS_MUS_WS_WINDOW_MANAGER_DISPLAY_ROOT_H_