a few small refactorings to closure workarounds

lib/src/codegen/js_metalet.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.
 
 // TODO(jmesserly): import from its own package
 import '../js/js_ast.dart';
 import '../js/precedence.dart';
 
 import 'js_names.dart' show TemporaryId;
 
@@ skipping 256 matching lines @@
 
     var newBody = new Expression.binary([assign]..addAll(body), ',');
     Binary comma = new Template(null, newBody).safeCreate({name: left});
     return new MetaLet(vars, comma.commaToExpressionList(),
         statelessResult: statelessResult);
   }
 }
 
 class _VariableUseCounter extends BaseVisitor {
   final counts = <String, int>{};
-  @override visitInterpolatedExpression(InterpolatedExpression node) {
+  @override
+  visitInterpolatedExpression(InterpolatedExpression node) {
     int n = counts[node.nameOrPosition];
     counts[node.nameOrPosition] = n == null ? 1 : n + 1;
   }
 }
 
 class _IdentFinder extends BaseVisitor {
   final String name;
   bool found = false;
   _IdentFinder(this.name);
 
-  @override visitIdentifier(Identifier node) {
+  @override
+  visitIdentifier(Identifier node) {
     if (node.name == name) found = true;
   }
 
-  @override visitNode(Node node) {
+  @override
+  visitNode(Node node) {
     if (!found) super.visitNode(node);
   }
 }
 
 class _YieldFinder extends BaseVisitor {
   bool hasYield = false;
   bool hasThis = false;
   bool _nestedFunction = false;
-  @override visitThis(This node) {
+  @override
+  visitThis(This node) {
     hasThis = true;
   }
 
-  @override visitFunctionExpression(FunctionExpression node) {
+  @override
+  visitFunctionExpression(FunctionExpression node) {
     var savedNested = _nestedFunction;
     _nestedFunction = true;
     super.visitFunctionExpression(node);
     _nestedFunction = savedNested;
   }
 
-  @override visitYield(Yield node) {
+  @override
+  visitYield(Yield node) {
     if (!_nestedFunction) hasYield = true;
   }
 
-  @override visitNode(Node node) {
+  @override
+  visitNode(Node node) {
     if (!hasYield) super.visitNode(node);
   }
 }