Add |id| and |anticipatedRemoval| fields to deprecation reports.

This patch changes the way that deprecation messages are stored in
Deprecation.cpp, such that each deprecated feature is also given a
unique id and anticipated removal milestone. This info is then used to
populate two new fields in deprecation reports: |id| and
|anticipatedRemoval|. These new fields are only available to
ReportingObserver so far, and will be routed to Reporting API in a
subsequent patch.

Bug: 731810, 564071
Change-Id: I3250bf940216238c531c3ec358539863598e3003
Reviewed-on: https://chromium-review.googlesource.com/772999
Commit-Queue: Paul Meyer <paulmeyer@chromium.org>
Reviewed-by: Rick Byers <rbyers@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519028}
6 files changed