Refuse to render RSS as XML by treating the response as text/plain. This is...

chrome/browser/renderer_host/buffered_resource_handler.cc

 // Copyright (c) 2009 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 "chrome/browser/renderer_host/buffered_resource_handler.h"
 
 #include "base/histogram.h"
 #include "base/logging.h"
 #include "base/string_util.h"
 #include "net/base/mime_sniffer.h"
@@ skipping 160 matching lines @@
   }
 
   if (sniffing_blocked && mime_type.empty() && !no_data) {
     // Ugg.  The server told us not to sniff the content but didn't give us a
     // mime type.  What's a browser to do?  Turns out, we're supposed to treat
     // the response as "text/plain".  This is the most secure option.
     mime_type.assign("text/plain");
     response_->response_head.mime_type.assign(mime_type);
   }
 
+  if (mime_type == "application/rss+xml" ||
+      mime_type == "application/atom+xml") {
+    // Sad face.  The server told us that they wanted us to treat the response
+    // as RSS or Atom.  Unfortunately, we don't have a built-in feed previewer
+    // like other browsers.  We can't just render the content as XML because
+    // web sites let third parties inject arbitrary script into their RSS
+    // feeds.  That leaves us with little choice but to practically ignore the
+    // response.  In the future, when we have an RSS feed previewer, we can
+    // remove this logic.
+    mime_type.assign("text/plain");
+    response_->response_head.mime_type.assign(mime_type);
+  }
+
   if (ShouldBuffer(request_->url(), mime_type)) {
     // This is a temporary fix for the fact that webkit expects to have
     // enough data to decode the doctype in order to select the rendering
     // mode.
     should_buffer_ = true;
     LOG(INFO) << "To buffer: " << request_->url().spec();
     return true;
   }
 
   if (!no_data && ShouldWaitForPlugins()) {
@@ skipping 242 matching lines @@
   wait_for_plugins_ = false;
   if (request_) {
     ResourceDispatcherHostRequestInfo* info =
         ResourceDispatcherHost::InfoForRequest(request_);
     host_->PauseRequest(info->child_id(), info->request_id(), false);
     if (!CompleteResponseStarted(info->request_id(), false))
       host_->CancelRequest(info->child_id(), info->request_id(), false);
   }
   Release();
 }