Remove out-of-date TODO item.
Use the FILE_PATH_LITERAL macro on the hardcoded paths.
Transform RefCounted into a template.
Transform RefCountedThreadSafe into a template.
Transform RefCountedThreadSafe into a template.
Remove not doable TODO item.
Make the Add/ReleaseWeakRef visible only to WeakOwnershipPolicy.
Remove TODO item (won't support Atomic<bool>).