Have each SandboxedProcessLauncherDelegate maintain a zygote.

content/public/browser/zygote_handle_linux.h

Index: content/public/browser/zygote_handle_linux.h
diff --git a/content/public/browser/zygote_handle_linux.h b/content/public/browser/zygote_handle_linux.h
new file mode 100644
index 0000000000000000000000000000000000000000..b644c514b60775ae4c1c03cb73b3e15a53e5e315
--- /dev/null
+++ b/content/public/browser/zygote_handle_linux.h
@@ -0,0 +1,21 @@
+// Copyright 2016 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_PUBLIC_BROWSER_ZYGOTE_HANDLE_LINUX_H_
+#define CONTENT_PUBLIC_BROWSER_ZYGOTE_HANDLE_LINUX_H_
+
+#include <cstddef>
+
+#include "content/common/content_export.h"
+#include "content/public/common/zygote_handle.h"
+
+namespace content {
+
+// Allocates and initializes a zygote process, and returns the
+// ZygoteHandle used to communicate with it.
+CONTENT_EXPORT ZygoteHandle CreateZygote();
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_ZYGOTE_HANDLE_LINUX_H_