Have each SandboxedProcessLauncherDelegate maintain a zygote.

content/browser/utility_process_host_impl.cc

Index: content/browser/utility_process_host_impl.cc
diff --git a/content/browser/utility_process_host_impl.cc b/content/browser/utility_process_host_impl.cc
index 3b7891f0c1f538beaa059c5b9b04f85e78fd4547..50d0217789b0fbeb6baec12ffe52b82a47d9cc19 100644
--- a/content/browser/utility_process_host_impl.cc
+++ b/content/browser/utility_process_host_impl.cc
@@ -58,7 +58,9 @@ class UtilitySandboxedProcessLauncherDelegate
         launch_elevated_(launch_elevated)
 #elif defined(OS_POSIX)
         env_(env),
+#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
         no_sandbox_(no_sandbox),
+#endif  // !defined(OS_MACOSX)  && !defined(OS_ANDROID)
         ipc_fd_(host->TakeClientFileDescriptor())
 #endif  // OS_WIN
   {}
@@ -88,9 +90,14 @@ class UtilitySandboxedProcessLauncherDelegate
 
 #elif defined(OS_POSIX)
 
-  bool ShouldUseZygote() override {
-    return !no_sandbox_ && exposed_dir_.empty();
+#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
+  ZygoteHandle* GetZygote() override {
+    if (no_sandbox_ || !exposed_dir_.empty())
+      return nullptr;
+    static ZygoteHandle zygote;
+    return &zygote;
   }
+#endif  // !defined(OS_MACOSX) && !defined(OS_ANDROID)
   base::EnvironmentMap GetEnvironment() override { return env_; }
   base::ScopedFD TakeIpcFd() override { return std::move(ipc_fd_); }
 #endif  // OS_WIN
@@ -106,7 +113,9 @@ class UtilitySandboxedProcessLauncherDelegate
   bool launch_elevated_;
 #elif defined(OS_POSIX)
   base::EnvironmentMap env_;
+#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
   bool no_sandbox_;
+#endif  // !defined(OS_MACOSX) && !defined(OS_ANDROID)
   base::ScopedFD ipc_fd_;
 #endif  // OS_WIN
 };