dart2js: Use js('source') instead of js['source'] to invoke JS mini-parser

sdk/lib/_internal/compiler/implementation/js/builder.dart

 // Copyright (c) 2013, 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.
 
 // Utilities for building JS ASTs at runtime.  Contains a builder class
 // and a parser that parses part of the language.
 
 part of js;
 
 class JsBuilder {
   const JsBuilder();
 
-  Expression operator [](String source) {
+  Expression call(String source) {
     return new MiniJsParser(source).expression();
   }
 
-  // TODO(ahe): Remove this method.
-  Binary equals(Expression left, Expression right) {
-    return new Binary('==', left, right);
-  }
-
-  // TODO(ahe): Remove this method.
-  Binary strictEquals(Expression left, Expression right) {
-    return new Binary('===', left, right);
-  }
-
   LiteralString string(String value) => new LiteralString('"$value"');
 
   If if_(condition, thenPart, [elsePart]) {
     condition = toExpression(condition);
     return (elsePart == null)
         ? new If.noElse(condition, toStatement(thenPart))
         : new If(condition, toStatement(thenPart), toStatement(elsePart));
   }
 
   Return return_([value]) {
@@ skipping 48 matching lines @@
       return statement.toStatement();
     } else {
       throw new ArgumentError('statement');
     }
   }
 
   Expression toExpression(expression) {
     if (expression is Expression) {
       return expression;
     } else if (expression is String) {
-      return this[expression];
+      return this(expression);
     } else if (expression is num) {
       return new LiteralNumber('$expression');
     } else if (expression is bool) {
       return new LiteralBool(expression);
     } else if (expression is Map) {
       if (!expression.isEmpty) {
         throw new ArgumentError('expression should be an empty Map');
       }
       return new ObjectInitializer([]);
     } else {
@@ skipping 442 matching lines @@
 
   Expression expression() {
     Expression expression = parseVarDeclarationOrExpression();
     if (lastCategory != NONE || position != src.length) {
       throw new MiniJsParserError(
           this, "Unparsed junk: ${categoryToString(lastCategory)}");
     }
     return expression;
   }
 }