Adding instrumentation to locate the source of jankiness.

components/captive_portal/captive_portal_detector.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 "components/captive_portal/captive_portal_detector.h"
 
 #include "base/logging.h"
+#include "base/profiler/scoped_profile.h"
 #include "base/strings/string_number_conversions.h"
 #include "net/base/load_flags.h"
 #include "net/http/http_response_headers.h"
 #include "net/url_request/url_request_status.h"
 
 namespace captive_portal {
 
 const char CaptivePortalDetector::kDefaultURL[] =
     "http://www.gstatic.com/generate_204";
 
@@ skipping 32 matching lines @@
       net::LOAD_DO_NOT_SEND_AUTH_DATA);
   url_fetcher_->Start();
 }
 
 void CaptivePortalDetector::Cancel() {
   url_fetcher_.reset();
   detection_callback_.Reset();
 }
 
 void CaptivePortalDetector::OnURLFetchComplete(const net::URLFetcher* source) {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/422577 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422577 CaptivePortalDetector::OnURLFetchComplete"));
+
   DCHECK(CalledOnValidThread());
   DCHECK(FetchingURL());
   DCHECK_EQ(url_fetcher_.get(), source);
   DCHECK(!detection_callback_.is_null());
 
   Results results;
   GetCaptivePortalResultFromResponse(url_fetcher_.get(), &results);
   DetectionCallback callback = detection_callback_;
   url_fetcher_.reset();
   detection_callback_.Reset();
@@ skipping 69 matching lines @@
     return base::Time::Now();
   else
     return time_for_testing_;
 }
 
 bool CaptivePortalDetector::FetchingURL() const {
   return url_fetcher_.get() != NULL;
 }
 
 }  // namespace captive_portal