WebRTC: Build Chromium with codecs

scripts/slave/recipes/chromium.expected/full_chromium_webrtc_Mac_Builder.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE[build]/bot_update.py",
       "--master",
       "chromium.webrtc",
       "--builder",
       "Mac Builder",
@@ skipping 98 matching lines @@
   },
   {
     "cmd": [
       "python",
       "-u",
       "[DEPOT_TOOLS]/gclient.py",
       "runhooks"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
-      "GYP_DEFINES": "blink_logging_always_on=1 clang=1 component=static_library dcheck_always_on=1 gomadir='[BUILD]/goma' target_arch=x64 use_goma=1"
+      "GYP_DEFINES": "blink_logging_always_on=1 clang=1 component=static_library dcheck_always_on=1 ffmpeg_branding=Chrome gomadir='[BUILD]/goma' proprietary_codecs=1 target_arch=x64 use_goma=1"
     },
     "name": "gclient runhooks"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/testing/scripts/get_compile_targets.py",
       "--output",
       "/path/to/tmp/json",
@@ skipping 139 matching lines @@
     "~followup_annotations": [
       "@@@STEP_TEXT@Mac Tester@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]