Before, the TransportConnectJob simply inferred that, if the main socket
failed to connect, the address it was using was the last address in the
list. With this change, the TCPClientSocket actually tracks all of the
connection attempts made (as it tries each address in the list), and the
TransportConnectJob copies the attempts from both the main and fallback
sockets and records all of them in the ClientSocketHandle in
GetAdditionalErrorState.

BUG=480565
TBR=jam

Review URL: https://codereview.chromium.org/1096203006

Cr-Commit-Position: refs/heads/master@{#330012}