GetAdditionalErrorState refactor 5, add method to get ConnectionAttempts

This CL adds a method to get a list of ConnectionAttempts from a
ConnectJob on error. As this was the only thing left that
ConnectJob::SetAdditionalErrorState retrieves, this CL removes that
method as well.

Bug: 927101
Change-Id: I2259215453cb0abd3d0e097dd9f684509fd1b9ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1559152
Reviewed-by: Asanka Herath <[email protected]>
Commit-Queue: Matt Menke <[email protected]>
Cr-Commit-Position: refs/heads/master@{#650028}
8 files changed