Implement support for link type serviceworker in link elements.

third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerError.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 55 matching lines @@
     case WebServiceWorkerError::ErrorTypeNotFound:
         return createException(NotFoundError, "The specified Service Worker resource was not found.", webError.message);
     case WebServiceWorkerError::ErrorTypeSecurity:
         return createException(SecurityError, "The Service Worker security policy prevented an action.", webError.message);
     case WebServiceWorkerError::ErrorTypeState:
         return createException(InvalidStateError, "The Service Worker state was not valid.", webError.message);
     case WebServiceWorkerError::ErrorTypeTimeout:
         return createException(AbortError, "The Service Worker operation timed out.", webError.message);
     case WebServiceWorkerError::ErrorTypeUnknown:
         return createException(UnknownError, "An unknown error occurred within Service Worker.", webError.message);
+    case WebServiceWorkerError::ErrorTypeType:
+        // ErrorTypeType should have been handled before reaching this point.
+        ASSERT_NOT_REACHED();
+        return DOMException::create(UnknownError);
     }
     ASSERT_NOT_REACHED();
     return DOMException::create(UnknownError);
 }
 
 } // namespace blink