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

net/http/http_stream_factory_impl_job_controller.cc

 // Copyright (c) 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/http/http_stream_factory_impl_job_controller.h"
 
 #include <string>
 #include <utility>
 
 #include "base/memory/ptr_util.h"
@@ skipping 603 matching lines @@
   if (is_preconnect_ || IsJobOrphaned(job))
     return;
 
   RemoveRequestFromSpdySessionRequestMap();
 }
 
 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_);
 }
 
 const NetLogWithSource* HttpStreamFactoryImpl::JobController::GetNetLog()
     const {
   return &net_log_;
 }
 
 void HttpStreamFactoryImpl::JobController::MaybeSetWaitTimeForMainJob(
@@ skipping 651 matching lines @@
     // If ReconsiderProxyAfterError() failed synchronously, it means
     // there was nothing left to fall-back to, so fail the transaction
     // with the last connection error we got.
     // TODO(eroman): This is a confusing contract, make it more obvious.
     rv = error;
   }
   return rv;
 }
 
 }  // namespace net