Make ProcessWatcher use kqueues on Mac.

chrome/common/process_watcher_posix.cc

 // Copyright (c) 2009 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/common/process_watcher.h"
 
 #include <errno.h>
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
@@ skipping 28 matching lines @@
   void ThreadMain() {
     WaitForChildToDie();
     delete this;
   }
 
   void WaitForChildToDie() {
     // Wait forever case.
     if (timeout_ == 0) {
       pid_t r = HANDLE_EINTR(waitpid(child_, NULL, 0));
       if (r != child_) {
-        LOG(ERROR) << "While waiting for " << child_
-                   << " to terminate, we got the following result: " << r;
+        PLOG(ERROR) << "While waiting for " << child_
+                    << " to terminate, we got the following result: " << r;
       }
       return;
     }
 
     // There's no good way to wait for a specific child to exit in a timed
     // fashion. (No kqueue on Linux), so we just loop and sleep.
 
     // Wait for 2 * timeout_ 500 milliseconds intervals.
     for (unsigned i = 0; i < 2 * timeout_; ++i) {
       PlatformThread::Sleep(500);  // 0.5 seconds
@@ skipping 15 matching lines @@
   const pid_t child_;
   // Number of seconds to wait, if 0 then wait forever and do not attempt to
   // kill |child_|.
   const unsigned timeout_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundReaper);
 };
 
 // static
 void ProcessWatcher::EnsureProcessTerminated(base::ProcessHandle process) {
-  // If the child is already dead, then there's nothing to do
+  // If the child is already dead, then there's nothing to do.
   if (IsChildDead(process))
     return;
 
   const unsigned timeout = 2;  // seconds
   BackgroundReaper* reaper = new BackgroundReaper(process, timeout);
   PlatformThread::CreateNonJoinable(0, reaper);
 }
 
 // static
 void ProcessWatcher::EnsureProcessGetsReaped(base::ProcessHandle process) {
-  // If the child is already dead, then there's nothing to do
+  // If the child is already dead, then there's nothing to do.
   if (IsChildDead(process))
     return;
 
   BackgroundReaper* reaper = new BackgroundReaper(process, 0);
   PlatformThread::CreateNonJoinable(0, reaper);
 }