The biggest changes are in pkg:observe where we picked up a lot of optimizations to PathObserver/CompoundObserver.
template_binding gets one-time bindings, synchronous expansion, and lightweight "bindable" objects.
The tests are heavily refactored to use Future instead of the hacky observeTest/performMicrotaskCheckpoint pattern (I have been slowly changing the style for new tests, but observe-js made the change for all of them. yay!). Oh and the performMC stuff is gone from pkg:observe now.
There's also a new pkg:polymer feature for observation, which was ported so we are at a consistent baseline. (http://www.polymer-project.org/polymer.html#observeblock)
R=justinfagnani@google.com, sigmund@google.com
Review URL: https://codereview.chromium.org//132403010
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@32342 260f80e4-7a28-3924-810f-c04153c831b5
jmesserly@google.com