Add support for "additional_mirrors" property in trybot configs.

tests/masters_recipes_test.py

Index: tests/masters_recipes_test.py
diff --git a/tests/masters_recipes_test.py b/tests/masters_recipes_test.py
index a1687e63d696ae9a3ee46cbf07987f3f4b086934..14fd367edfc6e972218d4588c80dff26e21f05dc 100755
--- a/tests/masters_recipes_test.py
+++ b/tests/masters_recipes_test.py
@@ -87,6 +87,15 @@ SUPPRESSIONS = {
 }
 
 
+# TODO(kbr): remove these suppressions. They're only needed
+# temporarily during the transition of the chromium.gpu bots to the
+# Chromium recipe, in order to achieve full code coverage while the
+# bots are actually running a different recipe.
+WRONG_RECIPE_SUPPRESSIONS = [
+  'GPU Linux Builder',
+  'Linux Release (NVIDIA)',
+]
+
 def getBuilders(recipe_name):
   """Asks the given recipe to dump its BUILDERS dictionary.
 
@@ -170,7 +179,8 @@ def main(argv):
         print '\n'.join('\t%s' % b for b in sorted(bogus_builders))
 
       other_recipe_builders = set(recipe_side_builders.keys()).difference(
-          set(chromium_recipe_builders[master]))
+          set(chromium_recipe_builders[master])).difference(
+            set(WRONG_RECIPE_SUPPRESSIONS))

[Sergey Berezin, 2016/01/06 01:50:56]

nit: 4 space indent for args

       if other_recipe_builders:
         exit_code = 1
         print 'The following builders from chromium recipe'