[NoStatePrefetch] Do not send responses to renderer in prefetch mode.

content/child/request_extra_data.cc

Index: content/child/request_extra_data.cc
diff --git a/content/child/request_extra_data.cc b/content/child/request_extra_data.cc
index e71362b75765f536dd165a0d6657b9944201b8b8..006d8502ce5d356f5b497781b27174e5c8459823 100644
--- a/content/child/request_extra_data.cc
+++ b/content/child/request_extra_data.cc
@@ -24,7 +24,9 @@ RequestExtraData::RequestExtraData()
       transferred_request_request_id_(-1),
       service_worker_provider_id_(kInvalidServiceWorkerProviderId),
       originated_from_service_worker_(false),
-      initiated_in_secure_context_(false) {}
+      initiated_in_secure_context_(false),
+      is_prefetch_(false),
+      download_to_network_cache_only_(false) {}
 
 RequestExtraData::~RequestExtraData() {
 }