GitLab

Expose TemplateURLPrepopulateData::GetCurrentCountryID() to detect that the
user changed the device region in order to update the list of search engine
on iOS.

Note that when a region change is detected we remove all default search
engines except the one selected by the user and then insert all the new
engines. This is possible because user cannot customize search engines,
only select one of the default engines.

BUG=None

Review URL: https://codereview.chromium.org/1130183004

Cr-Commit-Position: refs/heads/master@{#330716}