Force a crash of the browser if IO thread hasn't responded

chrome/browser/metrics/thread_watcher.cc

 // Copyright (c) 2011 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 "base/threading/thread_restrictions.h"
 #include "build/build_config.h"
 #include "chrome/browser/metrics/metrics_service.h"
 #include "chrome/browser/metrics/thread_watcher.h"
 #include "content/common/notification_service.h"
 
@@ skipping 251 matching lines @@
 
   // Record how many watched threads are responding.
   responsive_count_histogram_->Add(no_of_responding_threads);
 
   // Record how many watched threads are not responding.
   unresponsive_count_histogram_->Add(no_of_unresponding_threads);
 
   // Crash the browser if IO thread hasn't responded atleast kUnresponsiveCount
   // times and if the number of other threads is equal to 1. We picked 1 to
   // reduce the number of crashes and to get some sample data.
-  // if (thread_id_ == BrowserThread::IO && no_of_responding_threads == 1) {
-  //   int* crash = NULL;
-  //   CHECK(crash++);
-  // }
+  if (thread_id_ == BrowserThread::IO && no_of_responding_threads == 1) {
+    int* crash = NULL;
+    CHECK(crash++);
+  }
 
   hung_processing_complete_ = true;
 }
 
 // ThreadWatcherList methods and members.
 //
 // static
 ThreadWatcherList* ThreadWatcherList::global_ = NULL;
 // static
 const int ThreadWatcherList::kSleepSeconds = 2;
@@ skipping 253 matching lines @@
   watchdog_thread_ = NULL;
 }
 
 void WatchDogThread::CleanUpAfterMessageLoopDestruction() {
 #if defined(OS_WIN)
   // Closes the COM library on the current thread. CoInitialize must
   // be balanced by a corresponding call to CoUninitialize.
   CoUninitialize();
 #endif
 }