Adds a small icon to notifications, and connects it to synced notifications.

ui/message_center/message_center_style.h

Index: ui/message_center/message_center_style.h
diff --git a/ui/message_center/message_center_style.h b/ui/message_center/message_center_style.h
index 7aeadde4b3d1fc2de4835887d6b842f159af2a9e..170d489faeedaa8ecd4ebd83467f46c874caafda 100644
--- a/ui/message_center/message_center_style.h
+++ b/ui/message_center/message_center_style.h
@@ -22,6 +22,8 @@ const int kNotificationImageBorderSize = 10;
 const int kNotificationPreferredImageWidth = 360;
 const int kNotificationPreferredImageHeight = 240;
 const int kSettingsIconSize = 16;
+const int kSmallImageSize = 16;
+const int kSmallImagePadding = 4;
 
 // Limits.
 const size_t kMaxVisibleMessageCenterNotifications = 100;