ClientSocketPoolBaseTest to use MOCK_TIME

We're trying to migrate from the MessageLoop to the SequenceManager and
ClientSocketPoolBaseTest.TotalLimitCountsConnectingSockets fails on iOS
due to a quirk / feature / bug of MessagePumpIOSForIO.

MessagePumpIOSForIO isn't correctly handling SetNextDelayedDoWork
followed by a sleep and RunLoop().RunUntilIdle() properly. The problem
is upon entering the loop the MessagePumpCFRunLoopBase::PreWaitObserver
fires triggering DoIdleWork which triggers
ThreadControllerWithMessagePumpImpl to call Quit because QuitWhenIdle
has been requested.  In TotalLimitCountsConnectingSockets this
manifests as a reordering of the requests (order is 1,2,3,5,4).

I intend to try and fix MessagePumpIOSForIO but in the meantime I've
opted to modernise this test, which should unblock the
SequenceManager migration.

TBR=eroman@chromium.org

Bug: 863341, 891670
Change-Id: I7cf56dfb44a2601aa0eac7334e3a89ad3707d917
Reviewed-on: https://chromium-review.googlesource.com/c/1369773
Commit-Queue: Alex Clarke <alexclarke@chromium.org>
Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615094}
1 file changed