[telemetry] Cleanups for benchmarks importing page sets.

tools/telemetry/telemetry/core/discover.py

 # Copyright 2012 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 fnmatch
 import inspect
 import os
 import re
 
 from telemetry import decorators
@@ skipping 115 matching lines @@
 
 
 def IsPageSetFile(file_path):
   root_name, ext_name = os.path.splitext(file_path)
   if 'unittest' in root_name or 'page_sets/data' in root_name:
     return False
   if ext_name != '.py':
     return False
   module = util.GetPythonPageSetModule(file_path)
   return bool(DiscoverClassesInModule(module, page_set.PageSet))
-
-
-def GetAllPageSetFilenames(dir_path):
-  results = []
-  for sub_path, _, filenames in os.walk(dir_path):
-    for f in filenames:
-      if f.startswith('.'):
-        continue
-      filename = os.path.join(sub_path, f)
-      if IsPageSetFile(filename):
-        results.append(filename)
-  return results