ServiceWorker: add ServiceWorkerClients.claim() support (1/3).

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 47 matching lines @@
         return createException(NotSupportedError, "Service Worker support is disabled.", webError->message);
     case WebServiceWorkerError::ErrorTypeInstall:
         // FIXME: Introduce new InstallError type to ExceptionCodes?
         return createException(AbortError, "The Service Worker installation failed.", webError->message);
     case WebServiceWorkerError::ErrorTypeNetwork:
         return createException(NetworkError, "The Service Worker failed by network.", webError->message);
     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 operation failed by invalid state.", webError->message);

[mlamouri (slow - plz ping), 2015/01/23 10:08:08]

nit: the error message doesn't sound correct but I'm no native speaker

[jsbell, 2015/01/24 00:42:16]

+1

Given the text in the specification leading to this error, the message could be
one of:

"The Service Worker is not an active worker."

or:

"The operation failed because the Service Worker is not active."

[jsbell, 2015/01/24 01:15:01]

Ah, since this is just the default message, and the back end will provide the
real message in this failure case, this can be generic, e.g.:

"The Service Worker state was not valid."

... which isn't helpful, but that's fine since no-one should ever see it.

[falken, 2015/01/26 04:55:11]

Right, jsbell's message is good. We've actually historically showed these
generic messages but I'm working on providing more specific messages when
possible.

[xiang, 2015/01/26 06:47:54]

Done.

     case WebServiceWorkerError::ErrorTypeUnknown:
         return createException(UnknownError, "An unknown error occurred within Service Worker.", webError->message);
     }
     ASSERT_NOT_REACHED();
     return DOMException::create(UnknownError);
 }
 
 // static
 void ServiceWorkerError::dispose(WebType* webErrorRaw)
 {
     delete webErrorRaw;
 }
 
 } // namespace blink