Have each SandboxedProcessLauncherDelegate maintain a zygote.

content/public/common/sandboxed_process_launcher_delegate.cc

 // Copyright 2014 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 "build/build_config.h"
 #include "content/public/common/sandboxed_process_launcher_delegate.h"
 
 namespace content {
 
 #if defined(OS_WIN)
 bool SandboxedProcessLauncherDelegate::ShouldLaunchElevated() {
   return false;
 }
 
 bool SandboxedProcessLauncherDelegate::ShouldSandbox() {
   return true;
 }
 
 bool SandboxedProcessLauncherDelegate::DisableDefaultPolicy() {
   return false;
 }
 
 bool SandboxedProcessLauncherDelegate::PreSpawnTarget(
     sandbox::TargetPolicy* policy) {
   return true;
 }
 
 #elif(OS_POSIX)
-bool SandboxedProcessLauncherDelegate::ShouldUseZygote() {
-  return false;
+#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
+ZygoteHandle* SandboxedProcessLauncherDelegate::GetZygote() {
+  return nullptr;
 }
+#endif  // !defined(OS_MACOSX) && !defined(OS_ANDROID)
 
 base::EnvironmentMap SandboxedProcessLauncherDelegate::GetEnvironment() {
   return base::EnvironmentMap();
 }
 #endif
 
 SandboxType SandboxedProcessLauncherDelegate::GetSandboxType() {
   return SANDBOX_TYPE_INVALID;
 }
 
 }  // namespace content