Fix PRESUBMIT for long paths

Check all testable files, not just source files.

Bug: 1018801
Change-Id: I94e1fe78e57304dacaa59bb12d4004cffc7d6580
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1893503
Reviewed-by: Dirk Pranke <[email protected]>
Commit-Queue: Stephen Martinis <[email protected]>
Cr-Commit-Position: refs/heads/master@{#711505}
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 217e266..51abf03d 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -4317,7 +4317,7 @@
   This causes issues on Windows.
   """
   problems = []
-  for f in input_api.AffectedSourceFiles(None):
+  for f in input_api.AffectedTestableFiles():
     local_path = f.LocalPath()
     # Windows has a path limit of 260 characters. Limit path length to 200 so
     # that we have some extra for the prefix on dev machines and the bots.