merge_pr_46974

[SAA] refactor handling for code shared between rSA and rSA-extension

Turns out one needs to explicitly handle the rejection and not just
assume it bubbles up to the top. This makes sense given it would be bad
for web facing code to assume any error seen could be passed directly on
to the console.

This refactor allows logic to be shared between the two paths.

Fixed: 350653957
Change-Id: Ib0c7352c669641debbb177525746b8d9f7b7ebc9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5670735
Auto-Submit: Ari Chivukula arichiv@chromium.org
Reviewed-by: Chris Fredrickson cfredric@chromium.org
Commit-Queue: Ari Chivukula arichiv@chromium.org
Cr-Commit-Position: refs/heads/main@{#1322451}