Revert of Extend chromium_tests trigger to work across masters.

scripts/slave/recipe_modules/chromium_tests/bot_config_and_test_db.py

Index: scripts/slave/recipe_modules/chromium_tests/bot_config_and_test_db.py
diff --git a/scripts/slave/recipe_modules/chromium_tests/bot_config_and_test_db.py b/scripts/slave/recipe_modules/chromium_tests/bot_config_and_test_db.py
index 1bb2a0e770e83f2f48a2472dd58b804f782ffe34..527adacf5bee91e3641b5fba5f6fcadbc927f6b7 100644
--- a/scripts/slave/recipe_modules/chromium_tests/bot_config_and_test_db.py
+++ b/scripts/slave/recipe_modules/chromium_tests/bot_config_and_test_db.py
@@ -120,7 +120,7 @@
       bot_config = bot_db.get_bot_config(
           bot_id['mastername'], bot_id['buildername'])
 
-      for _, _, test_bot in bot_db.bot_configs_matching_parent_buildername(
+      for _, test_bot in bot_db.bot_configs_matching_parent_buildername(
           bot_id['mastername'], bot_id['buildername']):
         tests_including_triggered.extend(test_bot.get('tests', []))
 
@@ -182,20 +182,14 @@
     return self._db[mastername]['master_dict'].get('settings', {})
 
   def bot_configs_matching_parent_buildername(
-      self, parent_mastername, parent_buildername):
+      self, mastername, parent_buildername):
     """A generator of all the (buildername, bot_config) tuples whose
     parent_buildername is the passed one on the given master.
     """
-    for mastername, master_config in self._db.iteritems():
-      master_dict = self._db[parent_mastername]['master_dict']
-      for buildername, bot_config in master_dict.get(
-          'builders', {}).iteritems():
-        master_matches = (bot_config.get('parent_mastername', mastername) ==
-                          parent_mastername)
-        builder_matches = (bot_config.get('parent_buildername') ==
-                           parent_buildername)
-        if master_matches and builder_matches:
-          yield mastername, buildername, bot_config
+    for buildername, bot_config in self._db[mastername]['master_dict'].get(
+        'builders', {}).iteritems():
+      if bot_config.get('parent_buildername') == parent_buildername:
+        yield buildername, bot_config
 
   def get_test_spec(self, mastername, buildername):
     return self._db[mastername]['test_spec'].get(buildername, {})