Change EXPECT/ASSERT_DCHECK_DEATH macro to not expose the |regex| parameter.

base/threading/thread_unittest.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 "base/threading/thread.h"
 
 #include <stddef.h>
 
 #include <vector>
 
@@ skipping 303 matching lines @@
   a->StopSoon();
   base::PlatformThread::YieldCurrentThread();
   last_task_event.Wait();
   base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(20));
 
   // This test assumes that the above was sufficient to let the thread fully
   // stop.
   ASSERT_FALSE(a->IsRunning());
 
   // Restarting it should not be allowed.
-  EXPECT_DCHECK_DEATH(a->Start(), "");
+  EXPECT_DCHECK_DEATH(a->Start());
 }
 
 TEST_F(ThreadTest, ThreadName) {
   Thread a("ThreadName");
   EXPECT_TRUE(a.Start());
   EXPECT_EQ("ThreadName", a.thread_name());
 }
 
 TEST_F(ThreadTest, ThreadId) {
   Thread a("ThreadId0");
@@ skipping 129 matching lines @@
 
   a.Stop();
   EXPECT_FALSE(a.message_loop());
   EXPECT_FALSE(a.IsRunning());
 
   // Confirm that running any remaining tasks posted from Stop() goes smoothly
   // (e.g. https://codereview.chromium.org/2135413003/#ps300001 crashed if
   // StopSoon() posted Thread::ThreadQuitHelper() while |run_loop_| was null).
   base::RunLoop().RunUntilIdle();
 }