Remove dead code + trivial refactoring

Atomic is unnecessary here, boolean reads and writes are already atomic
and with "volatile" will always use main memory, so all writes will be
immediately visible to all threads. Atomic is also slower.

Bug: 335663055
Flag: EXEMPT removing dead code + trivial refactoring
Test: TreeHugger
Change-Id: I73e2e4674f81fea7bf790b6230c7281b783bb3c0