Add badge to web notifications.

content/browser/notifications/notification_database_data.proto

Index: content/browser/notifications/notification_database_data.proto
diff --git a/content/browser/notifications/notification_database_data.proto b/content/browser/notifications/notification_database_data.proto
index d47f5d98f1834faf492f94d12ef65b9bf2d8e53d..7044ed2f5c17d1e5581ab739976fcb227b11d3ca 100644
--- a/content/browser/notifications/notification_database_data.proto
+++ b/content/browser/notifications/notification_database_data.proto
@@ -30,7 +30,7 @@ message NotificationDatabaseDataProto {
   // Actual data payload of the notification. This message is the protocol
   // buffer meant to serialize the content::PlatformNotificationData structure.
   //
-  // Next tag: 14
+  // Next tag: 15
   message NotificationData {
     enum Direction {
       LEFT_TO_RIGHT = 0;
@@ -44,6 +44,7 @@ message NotificationDatabaseDataProto {
     optional string body = 4;
     optional string tag = 5;
     optional string icon = 6;
+    optional string badge = 14;
     repeated int32 vibration_pattern = 9 [packed=true];
     optional int64 timestamp = 12;
     optional bool renotify = 13;