Track UIApplication applicationState changes from a C++ class. Uses
NSNotificationCenter to access changes on the main thread and exposes
a local variable that can be checked from any thread.
This fixes a runtime warning on iOS 11 beta.
My Objective-C++ is a little rusty so please check if this follows
the conventions for C++ code in the project. It also changes the
interface exposed by RTCUIApplication.h, not sure if that has impact
on any public APIs that needs to be documented somewhere?
Bug: webrtc:7773
Change-Id: I9c8ba090ef9f28d812114026a906cef742192c39
Reviewed-on: https://chromium-review.googlesource.com/527442
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Reviewed-by: Kári Tristan Helgason <kthelgason@webrtc.org>
Commit-Queue: Anders Carlsson <andersc@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18558}
fc309750a9