Disable the content sniffing algorithm if the server instructs us to do so wi...

chrome/browser/resource_dispatcher_host.cc

 // Copyright (c) 2006-2008 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.
 
 // See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
 
 #include <vector>
 
 #include "chrome/browser/resource_dispatcher_host.h"
 
@@ skipping 1115 matching lines @@
       return false;
   }
 
   return real_handler_->OnReadCompleted(request_id, bytes_read);
 }
 
 bool ResourceDispatcherHost::BufferedEventHandler::DelayResponse() {
   std::string mime_type;
   request_->GetMimeType(&mime_type);
 
-  if (net::ShouldSniffMimeType(request_->url(), mime_type)) {
+  std::string content_type_options;
+  request_->GetResponseHeaderByName("x-content-type-options",
+                                    &content_type_options);
+  if (content_type_options != "nosniff" &&
+      net::ShouldSniffMimeType(request_->url(), mime_type)) {
     // We're going to look at the data before deciding what the content type
     // is.  That means we need to delay sending the ResponseStarted message
     // over the IPC channel.
     sniff_content_ = true;
     LOG(INFO) << "To buffer: " << request_->url().spec();
     return true;
   }
 
   if (ShouldBuffer(request_->url(), mime_type)) {
     // This is a temporary fix for the fact that webkit expects to have
@@ skipping 1361 matching lines @@
   bool enough_new_progress = (amt_since_last > (size / kHalfPercentIncrements));
   bool too_much_time_passed = time_since_last > kOneSecond;
 
   if (is_finished || enough_new_progress || too_much_time_passed) {
     info->event_handler->OnUploadProgress(info->request_id, position, size);
     info->waiting_for_upload_progress_ack = true;
     info->last_upload_ticks = TimeTicks::Now();
     info->last_upload_position = position;
   }
 }