Convert from base::{LazyInstance,Singleton} to base::NoDestructor

The class base::NoDestructor is a simpler way to define a static
global value (aka a singleton) than base::{LazyInstance,Singleton}
and is the recommended pattern to use.

The changes were automated using a custom one-shot script, then
fine tuned by hand (to remove unnecessary classes, ...).

This fixes usages in src/ios/chrome/browser/unified_consent.

This CL was uploaded by git cl split.

Bug: none
Change-Id: I3085ec3241fa416eef04fb249afbac94e1421063
Reviewed-on: https://chromium-review.googlesource.com/c/1411791
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Jérôme Lebel <jlebel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622911}
2 files changed