Make reprioritization IPC batch rather than per-request.

content/browser/loader/resource_dispatcher_host_impl.cc

 // Copyright (c) 2012 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.
 
 // See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
 
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 
 #include <stddef.h>
 
@@ skipping 1756 matching lines @@
 }
 
 void ResourceDispatcherHostImpl::OnReleaseDownloadedFile(
     ResourceRequesterInfo* requester_info,
     int request_id) {
   UnregisterDownloadedTempFile(requester_info->child_id(), request_id);
 }
 
 void ResourceDispatcherHostImpl::OnDidChangePriority(
     ResourceRequesterInfo* requester_info,
-    int request_id,
-    net::RequestPriority new_priority,
-    int intra_priority_value) {
-  ResourceLoader* loader = GetLoader(requester_info->child_id(), request_id);
-  // The request may go away before processing this message, so |loader| can
-  // legitimately be null.
-  if (!loader)
-    return;
+    const std::vector<ResourcePriorityChangeInfo>& priority_info_vector) {
+  std::vector<ResourceScheduler::PriorityChangeRequest>
+      priority_change_requests;
 
-  scheduler_->ReprioritizeRequest(loader->request(), new_priority,
-                                  intra_priority_value);
+  for (auto& v : priority_info_vector) {
+    ResourceLoader* loader =
+        GetLoader(requester_info->child_id(), v.request_id);
+    // The request may go away before processing this message, so |loader| can
+    // legitimately be null.
+    if (!loader)
+      continue;
+
+    priority_change_requests.push_back(
+        {loader->request(), v.priority, v.intra_priority_value});
+  }
+  scheduler_->ReprioritizeRequests(priority_change_requests);
 }
 
 void ResourceDispatcherHostImpl::RegisterDownloadedTempFile(
     int child_id, int request_id, const base::FilePath& file_path) {
   scoped_refptr<ShareableFileReference> reference =
       ShareableFileReference::Get(file_path);
   DCHECK(reference.get());
 
   registered_temp_files_[child_id][request_id] = reference;
   ChildProcessSecurityPolicyImpl::GetInstance()->GrantReadFile(
@@ skipping 1016 matching lines @@
                                  &throttles);
     if (!throttles.empty()) {
       handler.reset(new ThrottlingResourceHandler(std::move(handler), request,
                                                   std::move(throttles)));
     }
   }
   return handler;
 }
 
 }  // namespace content