Throttle HttpStreamFactoryImpl::Job to HTTP/2-supported servers

net/http/http_stream_factory_impl_job_controller.cc

Index: net/http/http_stream_factory_impl_job_controller.cc
diff --git a/net/http/http_stream_factory_impl_job_controller.cc b/net/http/http_stream_factory_impl_job_controller.cc
index 69209d4e4f8ef04c10442616f089adf27d079e6b..39671f774a30b11de03b6f809a3051531761a598 100644
--- a/net/http/http_stream_factory_impl_job_controller.cc
+++ b/net/http/http_stream_factory_impl_job_controller.cc
@@ -621,6 +621,13 @@ void HttpStreamFactoryImpl::JobController::
     RemoveRequestFromSpdySessionRequestMap() {
   // TODO(xunjieli): Use a DCHECK once https://crbug.com/718576 is fixed.
   CHECK(request_);
+  if (!request_->HasSpdySessionKey())
+    return;
+  // If the request failed or canceled, open the floodgate to resume all
+  // requests.
+  session_->spdy_session_pool()->ResumeAllPendingRequests(
+      request_->GetSpdySessionKey());
+
   session_->spdy_session_pool()->RemoveRequestFromSpdySessionRequestMap(
       request_);
 }