ios: Allow bot configs to set extra env variables

scripts/slave/recipe_modules/ios/api.py

Index: scripts/slave/recipe_modules/ios/api.py
diff --git a/scripts/slave/recipe_modules/ios/api.py b/scripts/slave/recipe_modules/ios/api.py
index 671f0bb6c85acb39ac946166a3f165ec4946116d..1c90295104387f4f447cec841d869dd55ee76fae 100644
--- a/scripts/slave/recipe_modules/ios/api.py
+++ b/scripts/slave/recipe_modules/ios/api.py
@@ -123,13 +123,13 @@ class iOSApi(recipe_api.RecipeApi):
     self.__config['GYP_DEFINES']['component'] = 'static_library'
     self.__config['GYP_DEFINES']['OS'] = 'ios'
 
-    # Because build configs are only required to specify "triggered bots" or
-    # "tests", one of them may not be specified. In order to simplify the code
-    # that uses the values of self.__config, here we default them both to empty
-    # values of their respective types, so in other places we can iterate over
-    # them without having to check if they are in the dict at all.
+    # In order to simplify the code that uses the values of self.__config, here
+    # we default to empty values of their respective types, so in other places
+    # we can iterate over them without having to check if they are in the dict
+    # at all.
     self.__config['triggered bots'] = self.__config.get('triggered bots', {})
     self.__config['tests'] = self.__config.get('tests', [])
+    self.__config['env'] = self.__config.get('env', {})
 
     # Elements of the "tests" list are dicts. There are two types of elements,
     # determined by the presence of one of these mutually exclusive keys:
@@ -224,6 +224,9 @@ class iOSApi(recipe_api.RecipeApi):
       'LANDMINES_VERBOSE': '1',
     }
 
+    # Add extra env variables.
+    env.update(self.__config['env'])
+
     if self.compiler == 'xcodebuild':
       env['GYP_GENERATORS'] = 'xcode'
       env['GYP_GENERATOR_FLAGS'] = 'xcode_project_version=3.2'