Socket Pools Refactor 11:  Flush TransportClientSocketPool on SSLConfig changes.

This is needed before SSLClientSockets can be moved to the
TransportClientSocketPool.

This is part of an effort to flatten the socket pools.
https://docs.google.com/document/d/1g0EA4iDqaDhNXA_mq-YK3SlSX-xRkoKvZetAQqdRrxM/edit

Bug: 472729
Change-Id: I99156dffc70d4859ae29c5e7335b9d1cb440dafd
Reviewed-on: https://chromium-review.googlesource.com/c/1423347
Commit-Queue: Matt Menke <[email protected]>
Reviewed-by: David Benjamin <[email protected]>
Cr-Commit-Position: refs/heads/master@{#626644}
12 files changed