This CL is a precursor to allowing shared writing to fix cache lock.
This CL allows transactions to continue to their validation phase even when another
transaction is the active reader/writer. After the validation phase, if its a match
the transaction might wait till the response is written to the cache by the active
writer. If its not a match the transaction will doom the entry and go to the
network. In a subsequent CL, the not matching case will create a new entry as well.
BUG=472740
Review-Url: https://codereview.chromium.org/2721933002
Cr-Commit-Position: refs/heads/master@{#467426}
11 files changed
