[ServiceWorker] Fills the referrer of WebServiceWorkerRequest.

content/renderer/service_worker/service_worker_script_context.cc

Index: content/renderer/service_worker/service_worker_script_context.cc
diff --git a/content/renderer/service_worker/service_worker_script_context.cc b/content/renderer/service_worker/service_worker_script_context.cc
index 59264e5df96a8d787522e2f32d56a71fe6e679b2..0f56e3fefd73c3dc8dd07a510bb1e74a69f4d41c 100644
--- a/content/renderer/service_worker/service_worker_script_context.cc
+++ b/content/renderer/service_worker/service_worker_script_context.cc
@@ -10,6 +10,7 @@
 #include "content/common/service_worker/service_worker_messages.h"
 #include "content/renderer/service_worker/embedded_worker_context_client.h"
 #include "ipc/ipc_message.h"
+#include "third_party/WebKit/public/platform/WebReferrerPolicy.h"
 #include "third_party/WebKit/public/platform/WebServiceWorkerRequest.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
@@ -135,6 +136,8 @@ void ServiceWorkerScriptContext::OnFetchEvent(
     webRequest.setHeader(blink::WebString::fromUTF8(it->first),
                          blink::WebString::fromUTF8(it->second));
   }
+  webRequest.setReferrer(blink::WebString::fromUTF8(request.referrer.spec()),
+                         blink::WebReferrerPolicyDefault);
   webRequest.setIsReload(request.is_reload);
   proxy_->dispatchFetchEvent(request_id, webRequest);
 }