Adding instrumentation to locate the source of jankiness.

net/url_request/url_request_job.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 "net/url_request/url_request_job.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop/message_loop.h"
 #include "base/power_monitor/power_monitor.h"
@@ skipping 485 matching lines @@
   tracked_objects::ScopedTracker tracking_profile10(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "423948 URLRequestJob::NotifyHeadersComplete 10"));
 
   request_->NotifyResponseStarted();
 }
 
 void URLRequestJob::NotifyReadComplete(int bytes_read) {
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION("URLRequestJob::NotifyReadComplete"));
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "423948 URLRequestJob::NotifyReadComplete"));
 
   if (!request_ || !request_->has_delegate())
     return;  // The request was destroyed, so there is no more work to do.
 
   // TODO(darin): Bug 1004233. Re-enable this test once all of the chrome
   // unit_tests have been fixed to not trip this.
 #if 0
   DCHECK(!request_->status().is_io_pending());
 #endif
   // The headers should be complete before reads complete
@@ skipping 418 matching lines @@
   // Alter the referrer if redirecting cross-origin (especially HTTP->HTTPS).
   redirect_info.new_referrer =
       ComputeReferrerForRedirect(request_->referrer_policy(),
                                  request_->referrer(),
                                  redirect_info.new_url).spec();
 
   return redirect_info;
 }
 
 }  // namespace net