Changes how window manager obtains WindowTree from mus

components/mus/ws/window_manager_window_tree_factory.h

Index: components/mus/ws/window_manager_window_tree_factory.h
diff --git a/components/mus/ws/window_manager_window_tree_factory.h b/components/mus/ws/window_manager_window_tree_factory.h
new file mode 100644
index 0000000000000000000000000000000000000000..7aed6c9dd19706bb130e77789b1a2a397392fca4
--- /dev/null
+++ b/components/mus/ws/window_manager_window_tree_factory.h
@@ -0,0 +1,75 @@
+// 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_WINDOW_TREE_FACTORY_H_
+#define COMPONENTS_MUS_WS_WINDOW_MANAGER_WINDOW_TREE_FACTORY_H_
+
+#include <stdint.h>
+
+#include <memory>
+
+#include "components/mus/public/interfaces/window_manager_window_tree_factory.mojom.h"
+#include "components/mus/ws/user_id.h"
+#include "mojo/public/cpp/bindings/binding.h"
+
+namespace mus {
+namespace ws {
+
+class ServerWindow;
+class WindowManagerWindowTreeFactorySet;
+class WindowServer;
+class WindowTree;
+
+namespace test {
+class WindowManagerWindowTreeFactorySetTestApi;
+}
+
+// Implementation of mojom::WindowManagerWindowTreeFactory.
+class WindowManagerWindowTreeFactory
+    : public mojom::WindowManagerWindowTreeFactory {
+ public:
+  WindowManagerWindowTreeFactory(
+      WindowManagerWindowTreeFactorySet* window_manager_window_tree_factory_set,
+      const UserId& user_id,
+      mojo::InterfaceRequest<mojom::WindowManagerWindowTreeFactory> request);
+  ~WindowManagerWindowTreeFactory() override;
+
+  const UserId& user_id() const { return user_id_; }
+
+  WindowTree* window_tree() { return window_tree_; }
+
+  void BindPendingRequest();
+
+  // mojom::WindowManagerWindowTreeFactory:
+  void CreateWindowTree(mojom::WindowTreeRequest window_tree_request,
+                        mojom::WindowTreeClientPtr window_tree_client) override;
+
+ private:
+  friend class test::WindowManagerWindowTreeFactorySetTestApi;
+  struct PendingRequest;
+
+  // Used by tests.
+  WindowManagerWindowTreeFactory(WindowManagerWindowTreeFactorySet* registry,
+                                 const UserId& user_id);
+
+  WindowServer* GetWindowServer();
+
+  void SetWindowTree(WindowTree* window_tree);
+
+  WindowManagerWindowTreeFactorySet* window_manager_window_tree_factory_set_;
+  const UserId user_id_;
+  mojo::Binding<mojom::WindowManagerWindowTreeFactory> binding_;
+
+  // Owned by WindowServer.
+  WindowTree* window_tree_;
+
+  std::unique_ptr<PendingRequest> pending_request_;
+
+  DISALLOW_COPY_AND_ASSIGN(WindowManagerWindowTreeFactory);
+};
+
+}  // namespace ws
+}  // namespace mus
+
+#endif  // COMPONENTS_MUS_WS_WINDOW_MANAGER_WINDOW_TREE_FACTORY_H_