[NOT FOR LANDING] Detailed loading traces

chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.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.
 
 #include "chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.h"
 
 #include <stdint.h>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 612 matching lines @@
                  ix->second.view_id, embedded));
   stream_target_info_.erase(request);
 #endif
 }
 
 void ChromeResourceDispatcherHostDelegate::OnResponseStarted(
     net::URLRequest* request,
     content::ResourceContext* resource_context,
     content::ResourceResponse* response,
     IPC::Sender* sender) {
+  TRACE_EVENT0("toplevel",
+               "ChromeResourceDispatcherHostDelegate::OnResponseStarted");
   const ResourceRequestInfo* info = ResourceRequestInfo::ForRequest(request);
   ProfileIOData* io_data = ProfileIOData::FromResourceContext(resource_context);
 
   // See if the response contains the X-Chrome-Manage-Accounts header. If so
   // show the profile avatar bubble so that user can complete signin/out action
   // the native UI.
   signin::ProcessMirrorResponseHeaderIfExists(request, io_data,
                                               info->GetChildID(),
                                               info->GetRouteID());
 
@@ skipping 86 matching lines @@
     return data_reduction_proxy_io_data->ShouldEnableLoFiMode(url_request);
   return false;
 }
 
 // static
 void ChromeResourceDispatcherHostDelegate::
     SetExternalProtocolHandlerDelegateForTesting(
     ExternalProtocolHandler::Delegate* delegate) {
   g_external_protocol_handler_delegate = delegate;
 }