Enable proprietary codecs and ffmpeg_branding=Chrome for Android.

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

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--master",
       "chromium.fyi",
       "--builder",
       "Android Builder (dbg)",
@@ skipping 88 matching lines @@
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE[depot_tools]/gclient.py",
       "runhooks"
     ],
     "cwd": "[SLAVE_BUILD]",
     "env": {
       "GYP_CROSSCOMPILE": "1",
-      "GYP_DEFINES": "OS=android component=static_library fastbuild=1 gomadir='[BUILD]/goma' target_arch=arm use_goma=1",
+      "GYP_DEFINES": "OS=android component=static_library fastbuild=1 ffmpeg_branding=Chrome gomadir='[BUILD]/goma' proprietary_codecs=1 target_arch=arm use_goma=1",
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s:RECIPE_PACKAGE[depot_tools]"
     },
     "name": "gclient runhooks"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/src/testing/scripts/get_compile_targets.py",
       "--output",
@@ skipping 290 matching lines @@
     "~followup_annotations": [
       "@@@STEP_TEXT@Android Tests (trial)(dbg)@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]