When a new request comes in to a socket pool, and that
request's group is stalled due to the pool hitting the
connection limit, try to close idle sockets in higher
level pools.

CLs to do this have been landed and reverted in the
past, due to crashes.  This CL attempts to avoid such
crashes by reducing re-entracy.  Idle sockets are closed
asynchronously, and the CL relies on that automatically
triggering use of the freed up socket slot.

BUG=92244

Review URL: https://codereview.chromium.org/14308013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@195540 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed