exo: Implement notification surface support

components/exo/display.h

Index: components/exo/display.h
diff --git a/components/exo/display.h b/components/exo/display.h
index 2d33a2e217cf567307af91d9e87bc3d35628c4f9..bce2072522cfc1c7c93618a89d226166df483a8f 100644
--- a/components/exo/display.h
+++ b/components/exo/display.h
@@ -8,6 +8,7 @@
 #include <stddef.h>
 
 #include <memory>
+#include <string>
 
 #include "base/macros.h"
 #include "base/memory/shared_memory_handle.h"
@@ -23,6 +24,8 @@ class Point;
 }
 
 namespace exo {
+class NotificationSurface;
+class NotificationSurfaceManager;
 class SharedMemory;
 class ShellSurface;
 class SubSurface;
@@ -78,7 +81,18 @@ class Display {
   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);
+
+  // Sets a NotificationSurfaceManager.
+  void SetNotificationSurfaceManager(
+      std::unique_ptr<NotificationSurfaceManager> notification_surface_manager);

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

nit: please change this to a raw pointer and have the caller manage the lifetime
of the manager instance

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

Sure. Since we would use a raw const pointer, it could need to be passed from
ctor. Thus removed this setter function.

+
  private:
+  std::unique_ptr<NotificationSurfaceManager> notification_surface_manager_;

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

nit: NotificationSurfaceManager* const notification_surface_manager_;

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

Done.

+
   DISALLOW_COPY_AND_ASSIGN(Display);
 };