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

content/renderer/render_view_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 "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/bind.h"
@@ skipping 3651 matching lines @@
   WebKit::WebReferrerPolicy referrer_policy;
   if (document_state && document_state->is_referrer_policy_set()) {
     referrer_policy = document_state->referrer_policy();
     document_state->clear_referrer_policy();
   } else {
     referrer_policy = frame->document().referrerPolicy();
   }
 
   // The request's extra data may indicate that we should set a custom user
   // agent. This needs to be done here, after WebKit is through with setting the
-  // user agent on its own.
+  // user agent on its own. Similarly, it may indicate that we should set an
+  // X-Requested-With header. This must be done here to avoid breaking CORS
+  // checks.
   WebString custom_user_agent;
+  WebString requested_with;
   if (request.extraData()) {
     webkit_glue::WebURLRequestExtraDataImpl* old_extra_data =
         static_cast<webkit_glue::WebURLRequestExtraDataImpl*>(
             request.extraData());
+
     custom_user_agent = old_extra_data->custom_user_agent();
-
     if (!custom_user_agent.isNull()) {
       if (custom_user_agent.isEmpty())
         request.clearHTTPHeaderField("User-Agent");
       else
         request.setHTTPHeaderField("User-Agent", custom_user_agent);
     }
+
+    requested_with = old_extra_data->requested_with();
+    if (!requested_with.isNull()) {
+      if (requested_with.isEmpty())
+        request.clearHTTPHeaderField("X-Requested-With");
+      else
+        request.setHTTPHeaderField("X-Requested-With", requested_with);
+    }
   }
 
   request.setExtraData(
       new RequestExtraData(referrer_policy,
                            custom_user_agent,
+                           requested_with,
                            (frame == top_frame),
                            frame->identifier(),
                            frame->parent() == top_frame,
                            frame->parent() ? frame->parent()->identifier() : -1,
                            navigation_state->allow_download(),
                            transition_type,
                            navigation_state->transferred_request_child_id(),
                            navigation_state->transferred_request_request_id()));
 
   DocumentState* top_document_state =
@@ skipping 2801 matching lines @@
 }
 #endif
 
 void RenderViewImpl::OnReleaseDisambiguationPopupDIB(
     TransportDIB::Handle dib_handle) {
   TransportDIB* dib = TransportDIB::CreateWithHandle(dib_handle);
   RenderProcess::current()->ReleaseTransportDIB(dib);
 }
 
 }  // namespace content