Oilpan: have LifetimeNotifier<T> track its observers weakly.
Simplify the unregistration of lifetime observers upon finalization by
having LifetimeNotifier<> keep a WeakMember<> reference to them. As a
result the observers will no longer have to explicitly unregister
themselves when going away. Observers can still explicitly unregister,
should that be needed for other reasons.
R=haraken
BUG=462949, 467502
Review URL: https://codereview.chromium.org/1006253002
git-svn-id: svn://svn.chromium.org/blink/trunk@192011 bbb929c8-8fbe-4397-9dbb-9b2b20218538
6 files changed
