Connect PPAPI IPC channels for non-SFI mode.

ipc/ipc_channel.h

Index: ipc/ipc_channel.h
diff --git a/ipc/ipc_channel.h b/ipc/ipc_channel.h
index 7e09a806f7a17bc111cce025081c253e7f37ebb3..71b22e7a05173dd1672d0e239ea386a9e11ad269 100644
--- a/ipc/ipc_channel.h
+++ b/ipc/ipc_channel.h
@@ -217,6 +217,15 @@ class IPC_EXPORT Channel : public Sender {
   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_