exo: Implement notification surface support

components/exo/display.h

 // Copyright 2015 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_DISPLAY_H_
 #define COMPONENTS_EXO_DISPLAY_H_
 
 #include <stddef.h>
 
 #include <memory>
+#include <string>
 
 #include "base/macros.h"
 #include "base/memory/shared_memory_handle.h"
 
 #if defined(USE_OZONE)
 #include "base/files/scoped_file.h"
 #include "ui/gfx/buffer_types.h"
 #include "ui/gfx/geometry/size.h"
 #endif
 
 namespace gfx {
 class Point;
 }
 
 namespace exo {
+class NotificationSurface;
 class SharedMemory;
 class ShellSurface;
 class SubSurface;
 class Surface;
 
 #if defined(USE_OZONE)
 class Buffer;
 #endif
 
 // The core display class. This class provides functions for creating surfaces
@@ skipping 35 matching lines @@
 
   // Creates a remote shell surface for an existing surface using |container|.
   std::unique_ptr<ShellSurface> CreateRemoteShellSurface(Surface* surface,
                                                          int container);
 
   // Creates a sub-surface for an existing surface. The sub-surface will be
   // a child of |parent|.
   std::unique_ptr<SubSurface> CreateSubSurface(Surface* surface,
                                                Surface* parent);
 
+  // Creates a notification surface for a surface and notification id.
+  std::unique_ptr<NotificationSurface> CreateNotificationSurface(
+      Surface* surface,
+      const std::string& notification_id);
+
  private:
   DISALLOW_COPY_AND_ASSIGN(Display);
 };
 
 }  // namespace exo
 
 #endif  // COMPONENTS_EXO_DISPLAY_H_