Make /gen/ available in wptserve

/gen/ is already available in both file tests (via
and http tests (via Apache 'Alias' directives). This CL makes /gen/ also
available to wptserve in Blink (both run_web_tests and

Besides, this CL adds configuration options (release, debug, etc.) to
run_blink_wptserve so that users can control which out/*/gen is served.

Also fix a leaking file descriptor in filesystem.open_text_tempfile.

Bug: 821496
Change-Id: I60ae0657df470dd319d002bc1c20476d33d9c05e
Commit-Queue: Robert Ma <>
Reviewed-by: Quinten Yearsley <>
Reviewed-by: Philip J├Ągenstedt <>
Cr-Commit-Position: refs/heads/master@{#576210}
4 files changed