Don't delay creation of system URLRequestContext until first use

chrome/test/base/testing_io_thread_state.cc

 // Copyright 2013 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/test/base/testing_io_thread_state.h"
 
 #include "base/location.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 78 matching lines @@
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   io_thread_state_->SetGlobalsForTesting(new IOThread::Globals());
 
   done.Run();
 }
 
 void TestingIOThreadState::Shutdown(const base::Closure& done) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-  delete io_thread_state_->globals();
-  io_thread_state_->SetGlobalsForTesting(NULL);
+  io_thread_state_->CleanUp();
   done.Run();
 }
 
 }  // namespace chrome