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

ui/message_center/message_center_impl.cc

 // Copyright (c) 2013 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.
 
 #include "ui/message_center/message_center_impl.h"
 
 #include <algorithm>
 
 #include "base/memory/scoped_vector.h"
 #include "base/observer_list.h"
@@ skipping 732 matching lines @@
     updated = notification_list_->SetNotificationButtonIcon(
         notification_id, button_index, image);
   }
 
   if (updated) {
     FOR_EACH_OBSERVER(MessageCenterObserver, observer_list_,
                       OnNotificationUpdated(notification_id));
   }
 }
 
+void MessageCenterImpl::SetNotificationSmallImage(
+    const std::string& notification_id,
+    const gfx::Image& image) {
+  bool updated = false;
+  Notification* queue_notification =
+      notification_queue_->GetLatestNotification(notification_id);
+
+  if (queue_notification) {
+    queue_notification->set_small_image(image);
+    updated = true;
+  } else {
+    updated =
+        notification_list_->SetNotificationSmallImage(notification_id, image);
+  }
+
+  if (updated) {
+    FOR_EACH_OBSERVER(MessageCenterObserver,
+                      observer_list_,
+                      OnNotificationUpdated(notification_id));
+  }
+}
+
 void MessageCenterImpl::DisableNotificationsByNotifier(
     const NotifierId& notifier_id) {
   if (settings_provider_) {
     // TODO(mukai): SetNotifierEnabled can just accept notifier_id?
     Notifier notifier(notifier_id, base::string16(), true);
     settings_provider_->SetNotifierEnabled(notifier, false);
   }
 
   NotificationList::Notifications notifications =
       notification_list_->GetNotificationsByNotifierId(notifier_id);
@@ skipping 117 matching lines @@
 void MessageCenterImpl::PausePopupTimers() {
   if (popup_timers_controller_.get())
     popup_timers_controller_->PauseAll();
 }
 
 void MessageCenterImpl::DisableTimersForTest() {
   popup_timers_controller_.reset();
 }
 
 }  // namespace message_center