Identify the hung thread using the Wait Chain Traversal API

chrome/browser/process_singleton_win.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/process_singleton.h"
 
 #include <windows.h>
 #include <shellapi.h>
 #include <stddef.h>
 
@@ skipping 205 matching lines @@
     enable_uploads = crash_reporter_client.GetCollectStatsConsent() &&
                      !crash_reporter_client.IsRunningUnattended();
   }
 
   if (!enable_uploads)
     return;
 
   // TODO(manzagop): add a metric for the number of captured hang reports, for
   //   comparison with uploaded count?
 
-  // Only report on canary (or unspecified).
-  const version_info::Channel channel = chrome::GetChannel();
-  if (channel != version_info::Channel::UNKNOWN &&
-      channel != version_info::Channel::CANARY) {
+  // Only report on canary.
+  if (chrome::GetChannel() != version_info::Channel::CANARY) {
     return;
   }
   // TODO(manzagop): add a metric for the number of times this does not match.
   if (!EnsureTargetProcessValidForCapture(process))
     return;
 
   // Initialize a reporter, capture a report and shutdown the reporter.
   base::FilePath watcher_data_directory;
   if (PathService::Get(chrome::DIR_WATCHER_DATA, &watcher_data_directory)) {
     base::string16 endpoint =
@@ skipping 195 matching lines @@
   return window_.hwnd() != NULL;
 }
 
 void ProcessSingleton::Cleanup() {
 }
 
 void ProcessSingleton::OverrideShouldKillRemoteProcessCallbackForTesting(
     const ShouldKillRemoteProcessCallback& display_dialog_callback) {
   should_kill_remote_process_callback_ = display_dialog_callback;
 }