libyuv: Switch bots over to GN by default.

scripts/slave/recipe_modules/libyuv/api.py

Index: scripts/slave/recipe_modules/libyuv/api.py
diff --git a/scripts/slave/recipe_modules/libyuv/api.py b/scripts/slave/recipe_modules/libyuv/api.py
index 792d1cb6c1e12cfe9e162f9a982186c5e1580ec8..599dae2aae4f4b816b4b469cf4ec691988dc1cd3 100644
--- a/scripts/slave/recipe_modules/libyuv/api.py
+++ b/scripts/slave/recipe_modules/libyuv/api.py
@@ -45,6 +45,9 @@ class LibyuvApi(recipe_api.RecipeApi):
     for c in self.bot_config.get('gclient_apply_config', []):
       self.m.gclient.apply_config(c)
 
+    if 'gyp' not in buildername.lower():
+      self.m.chromium.apply_config('gn')
+
     if self.m.tryserver.is_tryserver:
       self.m.chromium.apply_config('trybot_flavor')