R=vsm@google.com Review URL: https://codereview.chromium.org/1200233004.
This trims out a large chunk of the more obviously dart2js specific stuff from js_helper.dart and its dependencies. BUG= R=jmesserly@google.com, vsm@google.com Review URL: https://codereview.chromium.org/1152333009
it's all under input_sdk now: lib -> the lib folder private -> the dart:_* libs patch -> the files with @patch I imagine we'll try and focus changes on the last two