Do not trigger Lo-Fi on main frame requests

components/data_reduction_proxy/content/browser/content_lofi_decider.cc

 // Copyright 2015 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 "components/data_reduction_proxy/content/browser/content_lofi_decider.h"
 
 #include <string>
 
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
@@ skipping 59 matching lines @@
   // to other requests when previews are enabled. If previews are not enabled,
   // add "q=low".
   if (lofi_preview_via_flag_or_field_trial) {
     if (request.load_flags() & net::LOAD_MAIN_FRAME) {
       if (params::AreLoFiPreviewsEnabledViaFlags()) {
         header_value += chrome_proxy_lo_fi_ignore_preview_blacklist_directive();
         header_value += ", ";
       }
       header_value += chrome_proxy_lo_fi_preview_directive();
     }
-  } else {
+  } else if (!(request.load_flags() & net::LOAD_MAIN_FRAME)) {
+    // Do not add Lo-Fi header for main frame requests.
     header_value += chrome_proxy_lo_fi_directive();
   }
 
   // |header_value| may be empty because the Lo-Fi directive is not added
   // to subrequests when preview mode is enabled.

[megjablon, 2016/06/21 00:34:03]

Update this comment.

[tbansal1, 2016/06/22 18:08:38]

I removed the comment because it was incorrect. |header_value| is set in Line 63
above. So, even if there was nothing more was added to it, it may still be
non-empty.

   if (!header_value.empty())
     headers->SetHeader(chrome_proxy_header(), header_value);
 
   return true;
 }
 
 }  // namespace data_reduction_proxy