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

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

Index: ppapi/native_client/src/trusted/plugin/plugin.cc
===================================================================
--- ppapi/native_client/src/trusted/plugin/plugin.cc	(revision 136022)
+++ ppapi/native_client/src/trusted/plugin/plugin.cc	(working copy)
@@ -34,6 +34,7 @@
 #include "native_client/src/trusted/desc/nacl_desc_wrapper.h"
 #include "native_client/src/trusted/nonnacl_util/sel_ldr_launcher.h"
 #include "native_client/src/trusted/plugin/json_manifest.h"
+#include "native_client/src/trusted/plugin/nacl_entry_points.h"
 #include "native_client/src/trusted/plugin/nacl_subprocess.h"
 #include "native_client/src/trusted/plugin/nexe_arch.h"
 #include "native_client/src/trusted/plugin/plugin_error.h"
@@ -1214,6 +1215,11 @@
                    error_info->message().c_str()));
     return false;
   }
+
+  if (start_ppapi_proxy && start_ppapi_proxy(pp_instance())) {
+    return true;
+  }
+
   nacl::scoped_ptr<BrowserPpp> ppapi_proxy(new BrowserPpp(srpc_channel, this));
   PLUGIN_PRINTF(("Plugin::StartProxiedExecution (ppapi_proxy=%p)\n",
                  static_cast<void*>(ppapi_proxy.get())));