ServiceWorker: Use mojo's data pipe for respondWith(stream)

content/common/service_worker/service_worker_messages.h

Index: content/common/service_worker/service_worker_messages.h
diff --git a/content/common/service_worker/service_worker_messages.h b/content/common/service_worker/service_worker_messages.h
index 0f0356ab93655c49d50bcb16c33383429a234017..92a67773dfe6133aa8abb494435076a93d4cda56 100644
--- a/content/common/service_worker/service_worker_messages.h
+++ b/content/common/service_worker/service_worker_messages.h
@@ -92,7 +92,6 @@ IPC_STRUCT_TRAITS_BEGIN(content::ServiceWorkerResponse)
   IPC_STRUCT_TRAITS_MEMBER(headers)
   IPC_STRUCT_TRAITS_MEMBER(blob_uuid)
   IPC_STRUCT_TRAITS_MEMBER(blob_size)
-  IPC_STRUCT_TRAITS_MEMBER(stream_url)
   IPC_STRUCT_TRAITS_MEMBER(error)
   IPC_STRUCT_TRAITS_MEMBER(response_time)
   IPC_STRUCT_TRAITS_MEMBER(is_in_cache_storage)
@@ -245,9 +244,11 @@ IPC_MESSAGE_ROUTED4(ServiceWorkerHostMsg_InstallEventFinished,
                     bool /* has_fetch_event_handler */,
                     base::Time /* dispatch_event_time */)
 
-IPC_MESSAGE_ROUTED4(ServiceWorkerHostMsg_FetchEventResponse,
+// Returns the response as the result of fetch event. This is used only for blob
+// to keep the IPC ordering. Mojo IPC is used when the response body is a stream
+// or is empty, and for the fallback-to-network response.
+IPC_MESSAGE_ROUTED3(ServiceWorkerHostMsg_FetchEventResponse,
                     int /* fetch_event_id */,
-                    content::ServiceWorkerFetchEventResult,
                     content::ServiceWorkerResponse,
                     base::Time /* dispatch_event_time */)