GitLab

This CL adds the consent API that allows the various browser services to
check whether the user has consented for personalized URL-keyed data
collection (data collection that is keyed by URL and by Google account id).
As defined in the PRD, this decision is based on the sync state:
* If the Unified consent feature is disabled, then we consider that the
user has granted consent for personalized URL-keyed data collection iff sync
history is enabled.
* If the Unified consent feature is enabled, then we consider that the
user has granted consent for personalized URL-keyed data collection iff sync
user events is enabled (aka event logger is enabled).

BUG: 823809
Change-Id: Idf619b96010064020f36efbd90d54b720b45deec
Reviewed-on: https://chromium-review.googlesource.com/1123827
Commit-Queue: Mihai Sardarescu <msarda@chromium.org>
Reviewed-by: Thomas Tangl <tangltom@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572564}