Replace use of 'black_list' in //testing/PRESUBMIT.py

Should fix presubmit warnings.

R=dpranke

Change-Id: I767511e997d23a4a43e1dc2e25be567fca804c5a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2412895Reviewed-by: Dirk Pranke <dpranke@google.com>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#807283}

testing/PRESUBMIT.py

@@ -11,11 +11,10 @@ for more details on the presubmit API built into depot_tools.
 
 def CommonChecks(input_api, output_api):
   output = []
-  blacklist = [r'gmock.*', r'gtest.*']
   output.extend(input_api.canned_checks.RunUnitTestsInDirectory(
       input_api, output_api, '.', [r'^.+_unittest\.py$']))
   output.extend(input_api.canned_checks.RunPylint(
-      input_api, output_api, black_list=blacklist))
+      input_api, output_api, files_to_skip=[r'gmock.*', r'gtest.*']))
   return output