Ensure memory ordering around libagl and EGL refcount operations

The android_atomic_inc/android_atomic_dec functions don't impose
sufficient memory ordering. Using them for object refcounting could
allow an object to be destroyed prior to writes by a different thread
being visible.

Bug: 28820690
Change-Id: Ie018091035174255a22ebc52852528cdaec2d648
3 files changed