Generate a static struct from fieldtrial_testing_config

tools/perf/core/perf_benchmark.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 sys
 
 from telemetry import benchmark
 from telemetry.internal.browser import browser_finder
 
@@ skipping 33 matching lines @@
     if target_os.startswith('win'):
       return 'win'
     if target_os.startswith('linux'):
       return 'linux'
     return target_os
 
   def _GetVariationsBrowserArgs(self, finder_options):
     variations_dir = os.path.join(os.path.dirname(__file__), os.pardir,
         os.pardir, os.pardir, 'testing', 'variations')
     target_os = browser_finder.FindBrowser(finder_options).target_os
-    base_variations_path = os.path.join(variations_dir,
-        'fieldtrial_testing_config.json')
-    return fieldtrial_util.GenerateArgs(base_variations_path,
+    return fieldtrial_util.GenerateArgs(
         os.path.join(variations_dir,
         'fieldtrial_testing_config_%s.json' % self._FixupTargetOS(target_os)))