Implement modular compilation

lib/src/closure/closure_annotation.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import '../js/js_ast.dart' as JS show TypeRef, JsTypeRef, ClosureTypePrinter;
+import '../js_ast/js_ast.dart' as JS show TypeRef, ClosureTypePrinter;
 
 /// Set of closure annotations that can be [toString]ed to a single JsDoc comment.
 /// See https://developers.google.com/closure/compiler/docs/js-for-compiler
 ///
 /// TODO(ochafik): Support inclusion of 'normal' comments (including @param comments).
 class ClosureAnnotation {
   final String comment;
   final bool isConst;
   final bool isConstructor;
   final bool isFinal;
@@ skipping 109 matching lines @@
       if (isNonWildcard(throwsType))
         lines.add('@throws {${_print(throwsType)}}');
 
       if (lines.length == 0) return '';
       if (lines.length == 1) return '/** ${lines.single} */';
       __cachedString = '/**\n' + lines.map((l) => ' * $l').join('\n') + '\n */';
     }
     return __cachedString;
   }
 }