Fix build on Windows

Without this check, Python ends up spawning lots of Java processes and filling console with errors instead of building.

See https://stackoverflow.com/a/18205006.

Change-Id: Ia9956f649a59ec372dce675adcce31f072d8ee7f
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/1883723
Reviewed-by: Tim van der Lippe <tvanderlippe@chromium.org>
Commit-Queue: Ingvar Stepanyan <rreverser@google.com>
diff --git a/scripts/compile_frontend.py b/scripts/compile_frontend.py
index 564071d..ad264db 100755
--- a/scripts/compile_frontend.py
+++ b/scripts/compile_frontend.py
@@ -29,4 +29,5 @@
 
 from test import run_type_check
 
-run_type_check.main()
+if __name__ == '__main__':
+    run_type_check.main()