Cleanup JS() expressions. New Constructor for JsObject that preserves the correct prototype. Type check user-supplied values that pass through to JS(). Don't call _convertToJs(this)
Cleanup JS() expressions.
New Constructor for JsObject that preserves the correct prototype.
Type check user-supplied values that pass through to JS().
Don't call _convertToJs(this)

Based on: https://chromiumcodereview.appspot.com/26092003/

R=ahe@google.com, alexandre.ardhuin@gmail.com

Review URL: https://codereview.chromium.org//26270003

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@28813 260f80e4-7a28-3924-810f-c04153c831b5

dart-archive/browser