Create classes_util API, change discover to return a list instead of a dict.

content/test/gpu/gpu_tests/gpu_test_base_unittest.py

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 import os
 import unittest
 
-from telemetry.core import discover
+from telemetry.util import classes_util
 
 import gpu_test_base
 
 def _GetGpuDir(*subdirs):
   gpu_dir = os.path.dirname(os.path.dirname(__file__))
   return os.path.join(gpu_dir, *subdirs)
 
 #
 # Unit tests verifying invariants of classes in GpuTestBase.
 #
 
 class NoOverridesTest(unittest.TestCase):
   def testValidatorBase(self):
-    all_validators = discover.DiscoverClasses(
-      _GetGpuDir('gpu_tests'), _GetGpuDir(),
-      gpu_test_base.ValidatorBase,
-      index_by_class_name=True).values()
+    all_validators = classes_util.DiscoverClasses(
+      _GetGpuDir('gpu_tests'), _GetGpuDir(), gpu_test_base.ValidatorBase)
     self.assertGreater(len(all_validators), 0)
     for validator in all_validators:
       self.assertEquals(gpu_test_base.ValidatorBase.ValidateAndMeasurePage,
                         validator.ValidateAndMeasurePage,
                         'Class %s should not override ValidateAndMeasurePage'
                         % validator.__name__)
 
   def testPageBase(self):
-    all_pages = discover.DiscoverClasses(
-      _GetGpuDir(), _GetGpuDir(),
-      gpu_test_base.PageBase,
-      index_by_class_name=True).values()
+    all_pages = classes_util.DiscoverClasses(
+      _GetGpuDir(), _GetGpuDir(), gpu_test_base.PageBase)
     self.assertGreater(len(all_pages), 0)
     for page in all_pages:
       self.assertEquals(gpu_test_base.PageBase.RunNavigateSteps,
                         page.RunNavigateSteps,
                         'Class %s should not override ValidateAndMeasurePage'
                         % page.__name__)
       self.assertEquals(gpu_test_base.PageBase.RunPageInteractions,
                         page.RunPageInteractions,
                         'Class %s should not override RunPageInteractions'
                         % page.__name__)