Add a PepperHelper::EnablePepperSupportForChannel function to content.

chrome/browser/renderer_host/chrome_render_message_filter.h

Index: chrome/browser/renderer_host/chrome_render_message_filter.h
===================================================================
--- chrome/browser/renderer_host/chrome_render_message_filter.h	(revision 155271)
+++ chrome/browser/renderer_host/chrome_render_message_filter.h	(working copy)
@@ -22,6 +22,7 @@
 class GURL;
 
 namespace net {
+class HostResolver;
 class URLRequestContextGetter;
 }
 
@@ -68,6 +69,7 @@
 
   int render_process_id() { return render_process_id_; }
   bool off_the_record() { return off_the_record_; }
+  net::HostResolver* GetHostResolver();
 
  private:
   friend class content::BrowserThread;