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

Source/modules/serviceworkers/ServiceWorkerClients.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "modules/serviceworkers/ServiceWorkerClients.h"
 
 #include "bindings/core/v8/CallbackPromiseAdapter.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/ExceptionCode.h"
@@ skipping 55 matching lines @@
     if (options.type() != "window") {
         // FIXME: Currently we only support WindowClients.
         resolver->reject(DOMException::create(NotSupportedError, "type parameter of getAll is not supported."));
         return promise;
     }
 
     ServiceWorkerGlobalScopeClient::from(scriptState->executionContext())->getClients(new CallbackPromiseAdapter<ClientArray, ServiceWorkerError>(resolver));
     return promise;
 }
 
+ScriptPromise ServiceWorkerClients::claim(ScriptState* scriptState)
+{
+    ExecutionContext* executionContext = scriptState->executionContext();
+
+    // FIXME: May be null due to worker termination: http://crbug.coma/413518.
+    if (!executionContext)
+        return ScriptPromise();
+
+    RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromise promise = resolver->promise();
+
+    WebServiceWorkerClientsClaimCallbacks* callbacks = new CallbackPromiseAdapter<void, ServiceWorkerError>(resolver);
+    ServiceWorkerGlobalScopeClient::from(executionContext)->claim(callbacks);
+    return promise;
+}
+
 } // namespace blink