Add a blob field to ServiceWorkerFetchResponse and read the blob

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 18a555356fc50982069aa857c2abf1e7eb31bf93..509c85f406eed531dfdd7d04ff68e6521b2859aa 100644
--- a/content/renderer/service_worker/embedded_worker_context_client.cc
+++ b/content/renderer/service_worker/embedded_worker_context_client.cc
@@ -257,7 +257,8 @@ void EmbeddedWorkerContextClient::didHandleFetchEvent(
   }
   ServiceWorkerResponse response(web_response.status(),
                                  web_response.statusText().utf8(),
-                                 headers);
+                                 headers,
+                                 std::string());
   script_context_->DidHandleFetchEvent(
       request_id, SERVICE_WORKER_FETCH_EVENT_RESULT_RESPONSE, response);
 }