Add reprioritization to SSLConnectJobs

This change allows the priority of an SSLConnectJob to be changed. If
the reprioritization occurs while the job is establishing its underlying
connection, the priority change is also passed down to the lower-level
socket pool.

Bug: 166689
Change-Id: I87d1e536846443901cc628423f4615c3ffa7542a
Reviewed-on: https://chromium-review.googlesource.com/c/1327423
Commit-Queue: Lily Chen <chlily@chromium.org>
Reviewed-by: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606876}
5 files changed