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

ppapi/native_client/src/trusted/plugin/sel_ldr_launcher_chrome.cc

 // 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.
 
 #include "native_client/src/trusted/plugin/sel_ldr_launcher_chrome.h"
 
 #include "native_client/src/trusted/plugin/nacl_entry_points.h"
 
 LaunchNaClProcessFunc launch_nacl_process = NULL;
 
 namespace plugin {
 
 bool SelLdrLauncherChrome::Start(const char* url) {
+  return Start(0, url);
+}
+
+bool SelLdrLauncherChrome::Start(PP_Instance instance, const char* url) {
   // send a synchronous message to the browser process
   // TODO(sehr): This is asserted to be one.  Remove this parameter.
   static const int kNumberOfChannelsToBeCreated = 1;
   if (!launch_nacl_process ||
-      !launch_nacl_process(url, kNumberOfChannelsToBeCreated, &channel_)) {
+      !launch_nacl_process(instance,
+                           url,
+                           kNumberOfChannelsToBeCreated,
+                           &channel_)) {
     return false;
   }
   return true;
 }
 
 }  // namespace plugin