Add builder tag for Safari 6.2 slave. Update status files for Safari 6.2.

tools/testing/dart/status_expression.dart

 // Copyright (c) 2011, 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.
 
 library status_expression;
 
 /**
  * Parse and evaluate expressions in a .status file for Dart and V8.
  * There are set expressions and Boolean expressions in a .status file.
  * The grammar is:
@@ skipping 280 matching lines @@
     if (scanner.current == Token.LEFT_PAREN) {
       scanner.advance();
       BooleanExpression value = parseBooleanExpression();
       if (scanner.current != Token.RIGHT_PAREN) {
         throw new FormatException("Missing right parenthesis in expression");
       }
       scanner.advance();
       return value;
     }
 
-    // The only atomic booleans are of the form $variable == value or the
-    // form $variable.
+    // The only atomic booleans are of the form $variable == value or
+    // of the form $variable.
     if (scanner.current != Token.DOLLAR_SYMBOL) {
       throw new FormatException(
           "Expected \$ in expression, got ${scanner.current}");
     }
     scanner.advance();
     if (!new RegExp(r"^\w+$").hasMatch(scanner.current)) {
       throw new FormatException(
           "Expected identifier in expression, got ${scanner.current}");
     }
     TermVariable left = new TermVariable(scanner.current);
     scanner.advance();
     if (scanner.current == Token.EQUALS ||
         scanner.current == Token.NOT_EQUALS) {
       bool negate = scanner.current == Token.NOT_EQUALS;
       scanner.advance();
       if (!new RegExp(r"^\w+$").hasMatch(scanner.current)) {
         throw new FormatException(
-            "Expected identifier in expression, got ${scanner.current}");
+            "Expected value in expression, got ${scanner.current}");
       }
       TermConstant right = new TermConstant(scanner.current);
       scanner.advance();
       return new Comparison(left, right, negate);
     } else {
       return new BooleanVariable(left);
     }
   }
 }