Add a PepperHelper::EnablePepperSupportForChannel function to content.

chrome/browser/nacl_host/nacl_process_host.h

Index: chrome/browser/nacl_host/nacl_process_host.h
===================================================================
--- chrome/browser/nacl_host/nacl_process_host.h	(revision 154817)
+++ chrome/browser/nacl_host/nacl_process_host.h	(working copy)
@@ -24,6 +24,8 @@
 
 namespace content {
 class BrowserChildProcessHost;
+class RenderProcessHost;
+class ResourceContext;
 }
 
 namespace IPC {
@@ -136,6 +138,11 @@
   // the IPC proxy can be handled.
   bool OnUntrustedMessageForwarded(const IPC::Message& msg);
 
+  // Needed to access BrowserContext and ResourceContext.
+  void EnablePpapiChannelOnUIThread(int renderer_process_id);
+  // Needed to access HostResolver.
+  void EnablePpapiChannelOnIOThread(content::ResourceContext* resource_context);
+
   GURL manifest_url_;
 
 #if defined(OS_WIN)