Dispatch push event to worker from PushServiceImpl#OnMessage.

content/public/common/push_messaging_status.cc

Index: content/public/common/push_messaging_status.cc
diff --git a/content/public/common/push_messaging_status.cc b/content/public/common/push_messaging_status.cc
index 0040072bc0806e7ff883b298b2ca2a6ca8f894f3..f01cf80ca1fe4ef2f49ea17b6f45f25a5615c02a 100644
--- a/content/public/common/push_messaging_status.cc
+++ b/content/public/common/push_messaging_status.cc
@@ -28,6 +28,12 @@ const char* PushMessagingStatusToString(PushMessagingStatus status) {
     case PUSH_MESSAGING_STATUS_REGISTRATION_FAILED_SERVICE_ERROR:
       return "Registration failed - push service error";
 
+    case PUSH_MESSAGING_STATUS_MESSAGE_DELIVERY_FAILED_NO_SERVICE_WORKER:
+      return "Message delivery failed - no Service Worker";
+
+    case PUSH_MESSAGING_STATUS_MESSAGE_DELIVERY_FAILED_SERVICE_WORKER_ERROR:
+      return "Message delivery failed - Service Worker error";
+
     case PUSH_MESSAGING_STATUS_ERROR:
       return "Operation has failed (unspecified reason)";
   }