ServiceWorker: add ServiceWorkerClients.claim() support (2/3).

content/renderer/service_worker/embedded_worker_context_client.cc

Index: content/renderer/service_worker/embedded_worker_context_client.cc
diff --git a/content/renderer/service_worker/embedded_worker_context_client.cc b/content/renderer/service_worker/embedded_worker_context_client.cc
index eef9919b339070677665fea74d012ab203724b90..75b268015b9dd0cdb57e551ce4bcdb66d904c89d 100644
--- a/content/renderer/service_worker/embedded_worker_context_client.cc
+++ b/content/renderer/service_worker/embedded_worker_context_client.cc
@@ -397,6 +397,12 @@ void EmbeddedWorkerContextClient::skipWaiting(
   script_context_->SkipWaiting(callbacks);
 }
 
+void EmbeddedWorkerContextClient::claim(
+    blink::WebServiceWorkerClientsClaimCallbacks* callbacks) {
+  DCHECK(script_context_);
+  script_context_->ClaimClients(callbacks);
+}
+
 void EmbeddedWorkerContextClient::OnMessageToWorker(
     int thread_id,
     int embedded_worker_id,