GitLab

The existing aura::Env::GetInstance() doesn't create anything. Most
callers were using GetInstanceDontCreate() to mean HasInstance(), so
rename the method.

This makes it easier to write presubmits for aura::Env::GetInstance().

Bug: none
Test: bots
Change-Id: I0c606df7c8e439579d4ae39fa11dd119b610cb77
Reviewed-on: https://chromium-review.googlesource.com/1173473Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582906}