mypy fixes

tools/wpt/update_chromium_revision.py

@@ -33,9 +33,9 @@ def main(timeout: float = 600.0) -> None:
     # Step backwards through revision numbers until we find one
     # that is available for all platforms.
     candidate_revision = start_revision
-    new_revision = None
+    new_revision = -1
     timed_out = False
-    while not timed_out and new_revision is None:
+    while new_revision == -1 and candidate_revision > existing_revision:
         available_for_all = True
         # For each platform, check if Chromium is available for download from snapshots.
         for platform, filename in PLATFORM_INFO:
@@ -59,6 +59,7 @@ def main(timeout: float = 600.0) -> None:
             new_revision = candidate_revision
         if time() - start > timeout:
             timed_out = True
+            break
 
     if timed_out:
         raise TimeoutError(f"Reached timeout {timeout}s while checking revision "
@@ -80,4 +81,4 @@ def main(timeout: float = 600.0) -> None:
 
 
 if __name__ == "__main__":
-    main()  # type: ignore
+    main()