Use a single, generic, global zygote to temporarily resolve perf regressions.

chrome/browser/chrome_browser_main.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 "chrome/browser/chrome_browser_main.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <set>
 #include <string>
@@ skipping 1608 matching lines @@
 
 #if defined(OS_ANDROID)
   ThreadWatcherAndroid::RegisterApplicationStatusListener();
 #endif  // defined(OS_ANDROID)
 
 #if !defined(DISABLE_NACL)
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
       base::Bind(nacl::NaClProcessHost::EarlyStartup));
-
-#if defined(OS_POSIX) && !defined(OS_ANDROID) && !defined(OS_MACOSX)
-  BrowserThread::PostTask(BrowserThread::PROCESS_LAUNCHER, FROM_HERE,
-                          base::Bind(nacl::NaClProcessHost::EarlyZygoteLaunch));
-#endif  // defined(OS_POSIX) && !defined(OS_ANDROID) && !defined(OS_MACOSX)
 #endif  // !defined(DISABLE_NACL)
 
   // Make sure initial prefs are recorded
   PrefMetricsService::Factory::GetForProfile(profile_);
 
   PreBrowserStart();
 
   // Instantiate the notification UI manager, as this triggers a perf timer
   // used to measure startup time. TODO(stevenjb): Figure out what is actually
   // triggering the timer and call that explicitly in the approprate place.
@@ skipping 230 matching lines @@
   chromeos::CrosSettings::Shutdown();
 #endif  // defined(OS_CHROMEOS)
 #endif  // defined(OS_ANDROID)
 }
 
 // Public members:
 
 void ChromeBrowserMainParts::AddParts(ChromeBrowserMainExtraParts* parts) {
   chrome_extra_parts_.push_back(parts);
 }