Revert 255858 "Simplify the user agent code some more since afte..."

trunk/src/content/renderer/renderer_webkitplatformsupport_impl.cc

Index: trunk/src/content/renderer/renderer_webkitplatformsupport_impl.cc
===================================================================
--- trunk/src/content/renderer/renderer_webkitplatformsupport_impl.cc	(revision 255866)
+++ trunk/src/content/renderer/renderer_webkitplatformsupport_impl.cc	(working copy)
@@ -912,6 +912,11 @@
   }
 }
 
+blink::WebString RendererWebKitPlatformSupportImpl::userAgent(
+    const blink::WebURL& url) {
+  return WebKitPlatformSupportImpl::userAgent(url);
+}
+
 //------------------------------------------------------------------------------
 
 WebRTCPeerConnectionHandler*