Pepper: Add a X-Requested-With header to URL requests done for Pepper plugins.

webkit/glue/weburlrequest_extradata_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/glue/weburlrequest_extradata_impl.h"
 
 using WebKit::WebReferrerPolicy;
 using WebKit::WebString;
 
 namespace webkit_glue {
 
 WebURLRequestExtraDataImpl::WebURLRequestExtraDataImpl(
     WebReferrerPolicy referrer_policy,
-    const WebString& custom_user_agent)
+    const WebString& custom_user_agent,
+    const WebString& requested_with)
     : referrer_policy_(referrer_policy),
-      custom_user_agent_(custom_user_agent) {
+      custom_user_agent_(custom_user_agent),
+      requested_with_(requested_with) {
 }
 
 WebURLRequestExtraDataImpl::~WebURLRequestExtraDataImpl() {
 }
 
 }  // namespace webkit_glue