OOR-CORS: Skip CORS preflight cache if the original request wants

CORS preflight cache wasn't skipped regardless of the load_flags,
but with this change, it is skipped if the original request has
one of flags that want to skip caches.

Also, we do not store results to the cache if net::LOAD_DISABLE_CACHE
is specified.

Bug: 941297
Change-Id: Ibf356949dd6267eb65faf650d76b0c5e58ce5d5d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1520427
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Commit-Queue: Takashi Toyoshima <toyoshim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641113}
5 files changed