Remove custom filter for lint presubmit check.

The custom filter does not actually match against .cpp files. Rather
than debugging the problem, just delete it and fall back to the default
filter provided by depot_tools. The default `DEFAULT_FILES_TO_CHECK`
filter matches against more than just C++ files, but that is ok because
cpplint.py knows to ignore file extensions it does not understand.

Change-Id: Iba39ceaf37a43581971ddffd10bc71f299525fcf
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/79854
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 833d092..89c19b5 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -310,17 +310,13 @@
   return results
 
 def CheckChangeOnUpload(input_api, output_api):
-  cpp_source_filter = lambda x: input_api.FilterSourceFile(
-      x, files_to_check=(r'\.(?:c|cc|cpp|h)$',))
-
   results = []
   results.extend(_CheckUnwantedDependencies(input_api, output_api))
   results.extend(
       input_api.canned_checks.CheckPatchFormatted(input_api, output_api))
   results.extend(
-      input_api.canned_checks.CheckChangeLintsClean(input_api, output_api,
-                                                    cpp_source_filter,
-                                                    LINT_FILTERS))
+      input_api.canned_checks.CheckChangeLintsClean(
+          input_api, output_api, lint_filters=LINT_FILTERS))
   results.extend(_CheckIncludeOrder(input_api, output_api))
   results.extend(_CheckTestDuplicates(input_api, output_api))
   results.extend(_CheckPNGFormat(input_api, output_api))