Add appIconMask to notification API

chrome/common/extensions/api/notifications/notification_style.cc

Index: chrome/common/extensions/api/notifications/notification_style.cc
diff --git a/chrome/common/extensions/api/notifications/notification_style.cc b/chrome/common/extensions/api/notifications/notification_style.cc
index 5d2d8833e3e2615270dd67cb43f1d65474d3fc74..811d9a884f60fee7dca9aebd292b3410a1c311d6 100644
--- a/chrome/common/extensions/api/notifications/notification_style.cc
+++ b/chrome/common/extensions/api/notifications/notification_style.cc
@@ -6,6 +6,11 @@
 
 #include "ui/message_center/message_center_style.h"
 
+NotificationBitmapSizes::NotificationBitmapSizes() {
+}
+NotificationBitmapSizes::~NotificationBitmapSizes() {
+}
+
 NotificationBitmapSizes GetNotificationBitmapSizes() {
   NotificationBitmapSizes sizes;
   sizes.image_size =
@@ -16,5 +21,8 @@ NotificationBitmapSizes GetNotificationBitmapSizes() {
   sizes.button_icon_size =
       gfx::Size(message_center::kNotificationButtonIconSize,
                 message_center::kNotificationButtonIconSize);
+
+  sizes.app_icon_mask_size = gfx::Size(message_center::kSmallImageSize,
+                                       message_center::kSmallImageSize);
   return sizes;
 }