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

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

Index: ppapi/native_client/src/trusted/plugin/sel_ldr_launcher_chrome.cc
===================================================================
--- ppapi/native_client/src/trusted/plugin/sel_ldr_launcher_chrome.cc	(revision 136022)
+++ ppapi/native_client/src/trusted/plugin/sel_ldr_launcher_chrome.cc	(working copy)
@@ -11,11 +11,18 @@
 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;