[chrome.displaySource] Implement software based H.264 video encoder.

extensions/browser/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/features.gni")
 import("//extensions/extensions.gni")
 
 # GYP version: extensions/extensions.gyp:extensions_browser
 source_set("browser") {
   sources = []
@@ skipping 83 matching lines @@
         if (is_win || is_mac) {
           deps += [ "//components/wifi" ]
 
           win_or_mac_sources = rebase_path(
                   extensions_gypi_values.extensions_browser_sources_win_or_mac,
                   ".",
                   "//extensions")
           sources += win_or_mac_sources
         }
       }
-      if (enable_wifi_display) {
+      if (proprietary_codecs && enable_wifi_display) {
         wifi_display_sources = rebase_path(
                 extensions_gypi_values.extensions_browser_sources_wifi_display,
                 ".",
                 "//extensions")
         sources += wifi_display_sources
       }
     }
   }
 }