PpdProvidcer USB Fetching refactor

Rewrote OnUsbFetchComplete to no longer end the request on failure, i.e.
cedes back to MaybeStartNext...Resolution() to finish. This allows
future changes to only modify the latter function, centralizes the
logic.

Bug: none
Test: USB resolution tests still pass
Change-Id: Ib0253de6097d2bd90e8a1dd8cb30cbd11c2cf0b6
Reviewed-on: https://chromium-review.googlesource.com/c/1413910
Reviewed-by: Sean Kau <skau@chromium.org>
Commit-Queue: Luum Habtemariam <luum@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623565}
1 file changed