Connect PPAPI IPC channels for non-SFI mode.

ipc/ipc_channel.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 IPC_IPC_CHANNEL_H_
 #define IPC_IPC_CHANNEL_H_
 
 #include <string>
 
 #if defined(OS_POSIX)
@@ skipping 199 matching lines @@
   // no actual implementation is needed. This will cause un-overridden calls to
   // segfault. Do not use outside of test code!
   Channel() : channel_impl_(0) { }
 
  private:
   // PIMPL to which all channel calls are delegated.
   class ChannelImpl;
   ChannelImpl *channel_impl_;
 };
 
+#if defined(OS_LINUX)
+// On POSIX an IPC::Channel wraps a socketpair() with set some attributes
+// (such as non-blocking mode). This returns raw FD #s for the pair, which
+// allows us to pass file descriptors between processes (such as between
+// a plugin process and the browser process) before actual initialization
+// of IPC server Channel instance.
+bool SocketPair(int* fd1, int* fd2);
+#endif
+
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_H_