Changes how window manager obtains WindowTree from mus

components/mus/ws/window_manager_window_tree_factory_set.h

Index: components/mus/ws/window_manager_window_tree_factory_set.h
diff --git a/components/mus/ws/window_manager_window_tree_factory_set.h b/components/mus/ws/window_manager_window_tree_factory_set.h
new file mode 100644
index 0000000000000000000000000000000000000000..4d27a8868fb83c29bcc81a746fa37cc3f7442ef1
--- /dev/null
+++ b/components/mus/ws/window_manager_window_tree_factory_set.h
@@ -0,0 +1,94 @@
+// 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_SET_H_
+#define COMPONENTS_MUS_WS_WINDOW_MANAGER_WINDOW_TREE_FACTORY_SET_H_
+
+#include <stdint.h>
+
+#include <memory>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/observer_list.h"
+#include "components/mus/public/interfaces/window_manager_window_tree_factory.mojom.h"
+#include "components/mus/ws/user_id_tracker_observer.h"
+
+namespace mus {
+namespace ws {
+
+class UserIdTracker;
+class WindowManagerWindowTreeFactory;
+class WindowManagerWindowTreeFactorySetObserver;
+class WindowServer;
+class WindowTree;
+
+namespace test {
+class WindowManagerWindowTreeFactorySetTestApi;
+}
+
+// WindowManagerWindowTreeFactorySet tracks the set of registered
+// WindowManagerWindowTreeHostFactories.
+class WindowManagerWindowTreeFactorySet : public UserIdTrackerObserver {
+ public:
+  WindowManagerWindowTreeFactorySet(WindowServer* window_server,
+                                    UserIdTracker* tracker);
+  ~WindowManagerWindowTreeFactorySet() override;
+
+  WindowServer* window_server() { return window_server_; }
+
+  // Creates a new WindowManagerWindowTreeFactory for the specified user,
+  // unless one has been set, in which case the call is ignored. The newly
+  // created WindowManagerWindowTreeFactory does not immediately have a
+  // WindowTree associated with it.
+  WindowManagerWindowTreeFactory* Add(
+      const UserId& user_id,
+      mojo::InterfaceRequest<mojom::WindowManagerWindowTreeFactory> request);
+
+  // Deletes the WindowManagerWindowTreeFactory associated with |tree|. Does
+  // nothing if there is no WindowManagerWindowTreeFactory associated with
+  // |tree|.
+  void DeleteFactoryAssociatedWithTree(WindowTree* tree);
+
+  // Returns all the factories, even those that may not have a WindowTree
+  // associated with them.
+  std::vector<WindowManagerWindowTreeFactory*> GetFactories();
+
+  void AddObserver(WindowManagerWindowTreeFactorySetObserver* observer);
+  void RemoveObserver(WindowManagerWindowTreeFactorySetObserver* observer);
+
+ private:
+  friend class WindowManagerWindowTreeFactory;
+  friend class test::WindowManagerWindowTreeFactorySetTestApi;
+
+  // Returns true if a factory has been created for the specified user.
+  bool ContainsFactoryForUser(const UserId& user_id) const;
+
+  // Called by WindowManagerWindowTreeFactory when CreateWindowTree() has
+  // been called.
+  void OnWindowManagerWindowTreeFactoryReady(
+      WindowManagerWindowTreeFactory* factory);
+
+  // UserIdTrackerObserver:
+  void OnActiveUserIdChanged(const UserId& previously_active_id,
+                             const UserId& active_id) override;
+  void OnUserIdAdded(const UserId& id) override;
+  void OnUserIdRemoved(const UserId& id) override;
+
+  // Set to true the first time a valid factory has been found.
+  bool got_valid_factory_ = false;
+  UserIdTracker* id_tracker_;
+  WindowServer* window_server_;
+
+  std::vector<std::unique_ptr<WindowManagerWindowTreeFactory>> factories_;
+
+  base::ObserverList<WindowManagerWindowTreeFactorySetObserver> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(WindowManagerWindowTreeFactorySet);
+};
+
+}  // namespace ws
+}  // namespace mus
+
+#endif  // COMPONENTS_MUS_WS_WINDOW_MANAGER_WINDOW_TREE_FACTORY_SET_H_