Add support for fallback content for the frame. This includes main and subframes.

content/browser/service_worker/service_worker_url_loader_job.cc

Index: content/browser/service_worker/service_worker_url_loader_job.cc
diff --git a/content/browser/service_worker/service_worker_url_loader_job.cc b/content/browser/service_worker/service_worker_url_loader_job.cc
index 5eaf1a2ea282f3ff36be493601c003608b1bb3f3..68029f9bcb2c6e3d7dcc10969bced5703f216899 100644
--- a/content/browser/service_worker/service_worker_url_loader_job.cc
+++ b/content/browser/service_worker/service_worker_url_loader_job.cc
@@ -43,7 +43,7 @@ void ServiceWorkerURLLoaderJob::FallbackToNetwork() {
   // StartRequest cue like what URLRequestJob case does.
   // TODO(kinuko): Make sure this is ok or we need to make this async.
   if (!loader_callback_.is_null())
-    std::move(loader_callback_).Run(StartLoaderCallback());
+    std::move(loader_callback_).Run(StartLoaderCallback(), ResponseFallback());
 }
 
 void ServiceWorkerURLLoaderJob::FallbackToNetworkOrRenderer() {
@@ -251,13 +251,14 @@ void ServiceWorkerURLLoaderJob::DidDispatchFetchEvent(
   // ServiceWorker, we have to check the security level of the responses.
   const net::HttpResponseInfo* main_script_http_info =
       version->GetMainScriptHttpResponseInfo();
-  DCHECK(main_script_http_info);
-  ssl_info_ = main_script_http_info->ssl_info;
+  if (main_script_http_info)

[ananta, 2017/07/27 02:40:25]

Was hitting this DCHECK and the subsequent crash later on. Please check if this
change is ok.

[kinuko, 2017/07/27 13:46:27]

This should be fixed by my other change-
https://chromium-review.googlesource.com/c/584551/

If this doesn't break any other tests I prefer having the DCHECK as is
(otherwise could you put "TODO(kinuko): fix this" here)?

+    ssl_info_ = main_script_http_info->ssl_info;
 
   std::move(loader_callback_)
       .Run(base::Bind(&ServiceWorkerURLLoaderJob::StartResponse,
                       weak_factory_.GetWeakPtr(), response,
-                      base::Passed(std::move(body_as_stream))));
+                      base::Passed(std::move(body_as_stream))),
+           ResponseFallback());
 }
 
 void ServiceWorkerURLLoaderJob::StartResponse(