Fix PRESUMBIT_tests.py on Windows.

MockInputApi was returning MockFile objects instead of strings
from LocalPaths() API, which apparently trips up Windows Python
APIs, but not Unix ones.

Bug: 984360
Change-Id: I0a14cc07a9406d84d6b20d104d002fe67cc4ae86
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1706577
Reviewed-by: Dirk Pranke <[email protected]>
Reviewed-by: Gabriel Charette <[email protected]>
Commit-Queue: Alexei Svitkine <[email protected]>
Cr-Commit-Position: refs/heads/master@{#678454}
diff --git a/PRESUBMIT_test_mocks.py b/PRESUBMIT_test_mocks.py
index f641009..7fc3b2abc 100644
--- a/PRESUBMIT_test_mocks.py
+++ b/PRESUBMIT_test_mocks.py
@@ -111,7 +111,7 @@
     return found_in_white_list
 
   def LocalPaths(self):
-    return self.files
+    return [file.LocalPath() for file in self.files]
 
   def PresubmitLocalPath(self):
     return self.presubmit_local_path