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

content/browser/utility_process_host.h

 // 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.
 
 #ifndef CONTENT_BROWSER_UTILITY_PROCESS_HOST_H_
 #define CONTENT_BROWSER_UTILITY_PROCESS_HOST_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 48 matching lines @@
   // Starts utility process in batch mode. Caller must call EndBatchMode()
   // to finish the utility process.
   bool StartBatchMode();
 
   // Ends the utility process. Must be called after StartBatchMode().
   void EndBatchMode();
 
   void set_exposed_dir(const FilePath& dir) { exposed_dir_ = dir; }
   void set_no_sandbox(bool flag) { no_sandbox_ = flag; }
   void set_child_flags(int flags) { child_flags_ = flags; }
+  void set_use_linux_zygote(bool flag) { use_linux_zygote_ = flag; }
 #if defined(OS_POSIX)
   void set_env(const base::environment_vector& env) { env_ = env; }
 #endif
 
  protected:
   // Allow these methods to be overridden for tests.
   virtual FilePath GetUtilityProcessCmd();
 
  private:
   // Starts a process if necessary.  Returns true if it succeeded or a process
@@ skipping 16 matching lines @@
   // Allows a directory to be opened through the sandbox, in case it's needed by
   // the operation.
   FilePath exposed_dir_;
 
   // Whether to pass switches::kNoSandbox to the child.
   bool no_sandbox_;
 
   // Flags defined in ChildProcessHost with which to start the process.
   int child_flags_;
 
+  // If the |no_sandbox_| flag is off, and we are on Linux, launch the
+  // utility process from the zygote. Defaults to false.
+  // Can only be used for tasks that do not require FS access.
+  bool use_linux_zygote_;
+
   base::environment_vector env_;
 
   bool started_;
 
   DISALLOW_COPY_AND_ASSIGN(UtilityProcessHost);
 };
 
 #endif  // CONTENT_BROWSER_UTILITY_PROCESS_HOST_H_