Use UUID for ServiceWorker Client identifier (1/3, blink)

Source/modules/serviceworkers/ServiceWorkerWindowClient.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/ServiceWorkerWindowClient.h"
 
 #include "bindings/core/v8/CallbackPromiseAdapter.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/ExceptionCode.h"
@@ skipping 59 matching lines @@
 {
     RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
 
     if (!scriptState->executionContext()->isWindowInteractionAllowed()) {
         resolver->reject(DOMException::create(InvalidAccessError, "Not allowed to focus a window."));
         return promise;
     }
     scriptState->executionContext()->consumeWindowInteraction();
 
-    ServiceWorkerGlobalScopeClient::from(scriptState->executionContext())->focus(id(), new CallbackPromiseAdapter<ServiceWorkerWindowClient, ServiceWorkerError>(resolver));
+    if (!uuid().isEmpty()) {
+        ServiceWorkerGlobalScopeClient::from(scriptState->executionContext())->focus(uuid(), new CallbackPromiseAdapter<ServiceWorkerWindowClient, ServiceWorkerError>(resolver));
+    } else {
+        // FIXME: Deprecate this when we switch to uuid.
+        ServiceWorkerGlobalScopeClient::from(scriptState->executionContext())->focus(id(), new CallbackPromiseAdapter<ServiceWorkerWindowClient, ServiceWorkerError>(resolver));
+    }
     return promise;
 }
 
 DEFINE_TRACE(ServiceWorkerWindowClient)
 {
     ServiceWorkerClient::trace(visitor);
 }
 
 } // namespace blink