[Telemetry] Change the page's file_path param to base_dir param

content/test/gpu/gpu_tests/webgl_robustness.py

 # Copyright 2013 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.
 from telemetry import benchmark
 from telemetry.page import page
 from telemetry.page import page_set
 from telemetry.page import page_test
 
 from webgl_conformance import conformance_harness_script
 from webgl_conformance import conformance_path
@@ skipping 49 matching lines @@
 
 class WebglRobustness(benchmark.Benchmark):
   test = WebglConformanceValidator
 
   @classmethod
   def Name(cls):
     return 'webgl_robustness'
 
   def CreatePageSet(self, options):
     ps = page_set.PageSet(
-      file_path=conformance_path,
+      base_dir=conformance_path,
       user_agent_type='desktop',
       serving_dirs=[''])
     ps.AddUserStory(WebglRobustnessPage(ps, ps.base_dir))
     return ps