Disable ResultDB for test_runner.py on Windows

Temporarily disables ResultDB reporting for test_runner.py tests on
Windows. These tests run much slower in this configuration, and we're
still investigating why.

Bug: pdfium:1921
Change-Id: I24b7285a9750f11745fcdaaef60c5aeaf195d719
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/99374
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Auto-Submit: K. Moon <kmoon@chromium.org>
Commit-Queue: K. Moon <kmoon@chromium.org>
diff --git a/testing/tools/test_runner.py b/testing/tools/test_runner.py
index b1b1986..2c61745 100644
--- a/testing/tools/test_runner.py
+++ b/testing/tools/test_runner.py
@@ -10,6 +10,7 @@
 from dataclasses import dataclass
 import multiprocessing
 import os
+import platform
 import re
 import shutil
 import subprocess
@@ -432,6 +433,11 @@
     if self.resultdb:
       print('Detected ResultSink environment')
 
+      # TODO(crbug.com/pdfium/1921): Fix performance on Windows.
+      if platform.system() == 'Windows':
+        self.resultdb = None
+        print('Disabled ResultDB support due to https://crbug.com/pdfium/1921')
+
     # Collect test cases.
     walk_from_dir = finder.TestingDir(relative_test_dir)