exo: Implement notification surface support

components/exo/notification_surface_manager.h

Index: components/exo/notification_surface_manager.h
diff --git a/components/exo/notification_surface_manager.h b/components/exo/notification_surface_manager.h
new file mode 100644
index 0000000000000000000000000000000000000000..447af482bdd7af2d002da1c6a9fc67fc17c8d6fb
--- /dev/null
+++ b/components/exo/notification_surface_manager.h
@@ -0,0 +1,32 @@
+// 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_EXO_NOTIFICATION_SURFACE_REGISTRY_H_

[reveman, 2016/06/23 16:34:53]

nit: s/REGISTRY/MANAGER/

[xiyuan, 2016/06/23 17:46:09]

Done.

+#define COMPONENTS_EXO_NOTIFICATION_SURFACE_REGISTRY_H_

[reveman, 2016/06/23 16:34:53]

nit: s/REGISTRY/MANAGER/

[xiyuan, 2016/06/23 17:46:09]

Done.

+
+#include <string>
+
+namespace exo {
+
+class NotificationSurface;
+
+class NotificationSurfaceManager {
+ public:
+  // Gets the NotificationSurface associated with the given notification id.
+  // Returns nullptr if no NotificationSurface is associated with the id.
+  virtual NotificationSurface* GetSurface(
+      const std::string& notification_id) const = 0;
+
+  // Adds a NotificationSurface to the manager.
+  virtual void AddSurface(NotificationSurface* surface) = 0;
+
+  // Removes a NotificationSurface from the manager.
+  virtual void RemoveSurface(NotificationSurface* surface) = 0;
+
+  virtual ~NotificationSurfaceManager() {}

[reveman, 2016/06/23 16:34:53]

nit: please make this protected after changing SetNotificationSurfaceManager to
take a raw pointer

[xiyuan, 2016/06/23 17:46:09]

Done.

+};
+
+}  // namespace exo
+
+#endif  // COMPONENTS_EXO_NOTIFICATION_SURFACE_REGISTRY_H_

[reveman, 2016/06/23 16:34:53]

nit: s/REGISTRY/MANAGER/

[xiyuan, 2016/06/23 17:46:09]

Done.