Add a new priority level, THROTTLED, below IDLE.

content/browser/loader/async_revalidation_manager.cc

 // Copyright 2015 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 "content/browser/loader/async_revalidation_manager.h"
 
 #include <tuple>
 #include <utility>
 
 #include "base/logging.h"
@@ skipping 91 matching lines @@
     // A matching async revalidation is already in progress for this cache; we
     // don't need another one.
     return;
   }
 
   net::HttpRequestHeaders headers;
   headers.AddHeadersFromString(info->original_headers());
 
   // Construct the request.
   std::unique_ptr<net::URLRequest> new_request = request_context->CreateRequest(
-      for_request.url(), net::MINIMUM_PRIORITY, nullptr);
+      for_request.url(), net::IDLE, nullptr);
 
   new_request->set_method(for_request.method());
   new_request->set_first_party_for_cookies(
       for_request.first_party_for_cookies());
   new_request->set_initiator(for_request.initiator());
   new_request->set_first_party_url_policy(for_request.first_party_url_policy());
 
   new_request->SetReferrer(for_request.referrer());
   new_request->set_referrer_policy(for_request.referrer_policy());
 
@@ skipping 61 matching lines @@
 
   return true;
 }
 
 void AsyncRevalidationManager::OnAsyncRevalidationComplete(
     AsyncRevalidationMap::iterator it) {
   in_progress_.erase(it);
 }
 
 }  // namespace content