libyuv: Switch bots over to GN by default.

scripts/slave/recipes/libyuv/libyuv.expected/client_libyuv_android64_x64_debug.json

Index: scripts/slave/recipes/libyuv/libyuv.expected/client_libyuv_android64_x64_debug.json
diff --git a/scripts/slave/recipes/libyuv/libyuv.expected/client_libyuv_android64_x64_debug.json b/scripts/slave/recipes/libyuv/libyuv.expected/client_libyuv_android64_x64_debug.json
index 493420d478a497fe4ad5347dfffd1d683618334d..f5de9720bb5efe6e51c22f6986c16feef892ebc5 100644
--- a/scripts/slave/recipes/libyuv/libyuv.expected/client_libyuv_android64_x64_debug.json
+++ b/scripts/slave/recipes/libyuv/libyuv.expected/client_libyuv_android64_x64_debug.json
@@ -128,6 +128,7 @@
     "cwd": "[SLAVE_BUILD]/src",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json",
+      "GYP_CHROMIUM_NO_ACTION": "1",
       "GYP_CROSSCOMPILE": "1",
       "GYP_DEFINES": "OS=android component=static_library fastbuild=1 gomadir='[CACHE]/cipd/goma' target_arch=x64 use_goma=1",
       "PATH": "[SLAVE_BUILD]/src/third_party/android_tools/sdk/platform-tools:[SLAVE_BUILD]/src/build/android:%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
@@ -138,6 +139,19 @@
     "cmd": [
       "python",
       "-u",
+      "RECIPE_PACKAGE_REPO[depot_tools]/gn.py",
+      "--root=[SLAVE_BUILD]/src",
+      "gen",
+      "//out/Debug",
+      "--args=is_component_build=false is_debug=true target_os=\"android\" target_cpu=\"x64\" use_goma=true goma_dir=\"[CACHE]/cipd/goma\""
+    ],
+    "cwd": "[SLAVE_BUILD]/src",
+    "name": "gn"
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
       "RECIPE_PACKAGE_REPO[build]/scripts/tools/runit.py",
       "--show-path",
       "python",