Add a mechanism to launch the utility process from the zygote on Linux.

content/browser/utility_process_host.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 "content/browser/utility_process_host.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
@@ skipping 28 matching lines @@
     : BrowserChildProcessHost(content::PROCESS_TYPE_UTILITY),
       client_(client),
       client_thread_id_(client_thread_id),
       is_batch_mode_(false),
       no_sandbox_(false),
 #if defined(OS_LINUX)
       child_flags_(ChildProcessHost::CHILD_ALLOW_SELF),
 #else
       child_flags_(ChildProcessHost::CHILD_NORMAL),
 #endif
+      use_linux_zygote_(false),
       started_(false) {
 }
 
 UtilityProcessHost::~UtilityProcessHost() {
   DCHECK(!is_batch_mode_);
 }
 
 bool UtilityProcessHost::Send(IPC::Message* message) {
   if (!StartProcess())
     return false;
@@ skipping 63 matching lines @@
   if (has_cmd_prefix) {
     // launch the utility child process with some prefix (usually "xterm -e gdb
     // --args").
     cmd_line->PrependWrapper(browser_command_line.GetSwitchValueNative(
         switches::kUtilityCmdPrefix));
   }
 
   cmd_line->AppendSwitchPath(switches::kUtilityProcessAllowedDir, exposed_dir_);
 #endif
 
+  bool use_zygote = false;
+
+#if defined(OS_LINUX)
+  use_zygote = !no_sandbox_ && use_linux_zygote_;
+#endif
+
   Launch(
 #if defined(OS_WIN)
       exposed_dir_,
 #elif defined(OS_POSIX)
-      false,
+      use_zygote,
       env_,
 #endif
       cmd_line);
 
   return true;
 }
 
 bool UtilityProcessHost::OnMessageReceived(const IPC::Message& message) {
   BrowserThread::PostTask(
       client_thread_id_, FROM_HERE,
       base::IgnoreReturn<bool>(
           base::Bind(&Client::OnMessageReceived, client_.get(), message)));
   return true;
 }
 
 void UtilityProcessHost::OnProcessCrashed(int exit_code) {
   BrowserThread::PostTask(
       client_thread_id_, FROM_HERE,
       base::Bind(&Client::OnProcessCrashed, client_.get(), exit_code));
 }