Add a PepperHelper::EnablePepperSupportForChannel function to content.

chrome/browser/nacl_host/nacl_process_host.cc

Index: chrome/browser/nacl_host/nacl_process_host.cc
===================================================================
--- chrome/browser/nacl_host/nacl_process_host.cc	(revision 155271)
+++ chrome/browser/nacl_host/nacl_process_host.cc	(working copy)
@@ -34,6 +34,7 @@
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/browser_child_process_host.h"
 #include "content/public/browser/child_process_data.h"
+#include "content/public/browser/pepper_helper.h"
 #include "content/public/common/child_process_host.h"
 #include "ipc/ipc_channel.h"
 #include "ipc/ipc_switches.h"
@@ -711,8 +712,13 @@
                               IPC::Channel::MODE_CLIENT,
                               &ipc_plugin_listener_,
                               base::MessageLoopProxy::current()));
+    // Enable PPAPI message dispatching in the browser.
+    content::EnablePepperSupportForChannel(
+        ipc_proxy_channel_.get(),
+        chrome_render_message_filter_->render_process_id());
+
     // Send a message to create the NaCl-Renderer channel. The handle is just
-    // a place holder.
+    // a place holder, filled in by NaCl process trusted code.
     ipc_proxy_channel_->Send(
         new PpapiMsg_CreateNaClChannel(
             chrome_render_message_filter_->render_process_id(),