Update from https://crrev.com/320343

base/process/kill_mac.cc

 // Copyright (c) 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 "base/process/kill.h"
 
 #include <signal.h>
 #include <sys/event.h>
 #include <sys/types.h>
 #include <sys/wait.h>
@@ skipping 48 matching lines @@
 // mean that zombies be allowed to kick you while you're down.)
 //
 // The fact that this function seemingly can be called to wait on a child
 // that's not only already terminated but already reaped is a bit of a
 // problem: a reaped child's pid can be reclaimed and may refer to a distinct
 // process in that case. The fact that this function can seemingly be called
 // to wait on a process that's not even a child is also a problem: kqueue will
 // work in that case, but waitpid won't, and killing a non-child might not be
 // the best approach.
 void WaitForChildToDie(pid_t child, int timeout) {
-  DCHECK(child > 0);
-  DCHECK(timeout > 0);
+  DCHECK_GT(child, 0);
+  DCHECK_GT(timeout, 0);
 
   // DON'T ADD ANY EARLY RETURNS TO THIS FUNCTION without ensuring that
   // |child| has been reaped. Specifically, even if a kqueue, kevent, or other
   // call fails, this function should fall back to the last resort of trying
   // to kill and reap the process. Not observing this rule will resurrect
   // zombies.
 
   int result;
 
   ScopedFD kq(HANDLE_EINTR(kqueue()));
@@ skipping 82 matching lines @@
   }
 }
 
 }  // namespace
 
 void EnsureProcessTerminated(Process process) {
   WaitForChildToDie(process.Pid(), kWaitBeforeKillSeconds);
 }
 
 }  // namespace base