Remove getApplicationContext calls from sync

Continuation of work in bug 646094.
Preparing to activate an errorprone check to flag
context#getApplicationContext calls. The goal is to prevent storing the
resulting context as a class property, and instead use ContextUtils.

Bug: 846456
Change-Id: I0739a803ff80c38df73632f62298f83bb90d28f8
Reviewed-on: https://chromium-review.googlesource.com/1095974
Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Commit-Queue: Tiger Oakes <tigero@google.com>
Cr-Commit-Position: refs/heads/master@{#577890}
3 files changed