It2Me Host changes to support Confirmation Dialog state

This change adds a new state to the It2Me connection process.  This state
will be sent to the Webapp/client to indicate that the remote user has
started the connection process but has not yet completed it.  For our
purposes, this state will signal that the local user must take action
(i.e. click accept on the confirmation dialog) and we can use it to
updated the text / UI state on the local machine.

BUG=658459

Review-Url: https://codereview.chromium.org/2452223002
Cr-Commit-Position: refs/heads/master@{#428776}
5 files changed