Add an IPC channel between the NaCl loader process and the renderer.

chrome/nacl/nacl_ipc_adapter.cc

Index: chrome/nacl/nacl_ipc_adapter.cc
===================================================================
--- chrome/nacl/nacl_ipc_adapter.cc	(revision 143509)
+++ chrome/nacl/nacl_ipc_adapter.cc	(working copy)
@@ -74,6 +74,7 @@
                               int /* flags */) {
   if (msg->iov_length != 1)
     return -1;
+  msg->ndesc_length = 0;  // Messages with descriptors aren't supported yet.
   return static_cast<ssize_t>(
       ToAdapter(handle)->BlockingReceive(static_cast<char*>(msg->iov[0].base),
                                          msg->iov[0].length));
@@ -281,6 +282,12 @@
   return MakeNaClDescCustom(this);
 }
 
+#if defined(OS_POSIX)
+int NaClIPCAdapter::TakeClientFileDescriptor() {
+  return io_thread_data_.channel_->TakeClientFileDescriptor();
+}
+#endif
+
 bool NaClIPCAdapter::OnMessageReceived(const IPC::Message& message) {
   {
     base::AutoLock lock(lock_);