Move the Linux zygote stuff into its own per-process directory.

content/common/zygote_commands_linux.h

+// Copyright (c) 2012 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_COMMON_ZYGOTE_COMMANDS_LINUX_H_
+#define CONTENT_COMMON_ZYGOTE_COMMANDS_LINUX_H_
+
+namespace content {
+
+// Contents of the initial message sent from the zygote to the browser when it
+// is ready to go.
+static const char kZygoteHelloMessage[] = "ZYGOTE_OK";
+
+// These are the command codes used on the wire between the browser and the
+// zygote.
+enum {
+  // Fork off a new renderer.
+  kZygoteCommandFork = 0,
+
+  // Reap a renderer child.
+  kZygoteCommandReap = 1,
+
+  // Check what happend to a child process.
+  kZygoteCommandGetTerminationStatus = 2,
+
+  // Read a bitmask of kSandboxLinux*
+  kZygoteCommandGetSandboxStatus = 3
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_ZYGOTE_COMMANDS_LINUX_H_