Wait for tpcontrol to exit so we don't leave zombie processes hanging around.

chrome/browser/chromeos/system/touchpad_settings.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 "chrome/browser/chromeos/system/touchpad_settings.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
@@ skipping 13 matching lines @@
 
 bool TPCtrlExists() {
   return file_util::PathExists(FilePath(kTpControl));
 }
 
 // Launches the tpcontrol command asynchronously, if it exists.
 void LaunchTpControl(const std::vector<std::string>& argv) {
   if (!TPCtrlExists())
     return;
 
-  base::LaunchProcess(CommandLine(argv), base::LaunchOptions(), NULL);
+  base::LaunchOptions options;
+  options.wait = true;
+  base::LaunchProcess(CommandLine(argv), options, NULL);
 }
 
 }  // namespace
 
 bool TouchpadExists() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   static bool init = false;
   static bool exists = false;
 
   if (init)
@@ skipping 42 matching lines @@
   argv.push_back(kTpControl);
   argv.push_back("taptoclick");
   argv.push_back(enabled ? "on" : "off");
 
   LaunchTpControl(argv);
 }
 
 }  // namespace touchpad_settings
 }  // namespace system
 }  // namespace chromeos