Adding instrumentation to locate the source of jankiness.

components/translate/core/browser/translate_url_fetcher.cc

 // Copyright 2014 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/translate/core/browser/translate_url_fetcher.h"
 
+#include "base/profiler/scoped_profile.h"
 #include "components/translate/core/browser/translate_download_manager.h"
 #include "net/base/load_flags.h"
 #include "net/http/http_status_code.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_request_status.h"
 
 namespace translate {
 
 namespace {
 
@@ skipping 43 matching lines @@
   fetcher_->SetMaxRetriesOn5xx(max_retry_on_5xx_);
   if (!extra_request_header_.empty())
     fetcher_->SetExtraRequestHeaders(extra_request_header_);
 
   fetcher_->Start();
 
   return true;
 }
 
 void TranslateURLFetcher::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 TranslateURLFetcher::OnURLFetchComplete"));
+
   DCHECK(fetcher_.get() == source);
 
   std::string data;
   if (source->GetStatus().status() == net::URLRequestStatus::SUCCESS &&
       source->GetResponseCode() == net::HTTP_OK) {
     state_ = COMPLETED;
     source->GetResponseAsString(&data);
   } else {
     state_ = FAILED;
   }
 
   // Transfer URLFetcher's ownership before invoking a callback.
   scoped_ptr<const net::URLFetcher> delete_ptr(fetcher_.release());
   callback_.Run(id_, state_ == COMPLETED, data);
 }
 
 }  // namespace translate