A browser process launch with --try-chrome-again on the command line
will not report as an active Chrome session or a formal launch. Other
launches are unaffected. A subsequent rendez-vous to a browser process
started with --try-chrome-again will be counted as a formal launch and
will start reporting as an active session.

Previously, "dr" was reset on shutdown when --try-chrome-again was used
and the user chose not to run Chrome. Now, "dr" is not touched during
the initial browsing session containing --try-chrome-again on the
command line. This makes the reset unnecessary, and no longer counts
such launches as active under any circumstances. As above, subsequent
launches (or rendez-vous to the same process) will have "dr" set as
usual.

In the case of "lastrun", it was previously only set on initial browser
process startup. It is now also set for rendez-vous.

BUG=717091

Cq-Include-Trybots: master.tryserver.chromium.win:win10_chromium_x64_rel_ng
Change-Id: I68aa76d6457061d0799866cc705e18828ddf0db5
Reviewed-on: https://chromium-review.googlesource.com/525753


Commit-Queue: Greg Thompson <grt@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#479139}