removed unused 'prefix' line from status files

tools/testing/dart/status_file_parser.dart

 // Copyright (c) 2012, 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_file_parser");
 
 #import("dart:io");
 #import("status_expression.dart");
 
 // Possible outcomes of running a test.
 final CRASH = "crash";
 final TIMEOUT = "timeout";
 final FAIL = "fail";
 final PASS = "pass";
 // An indication to skip the test.  The caller is responsible for skipping it.
 final SKIP = "skip";
 final OK = "ok";
 
 final RegExp StripComment = const RegExp("^[^#]*");
 final RegExp HeaderPattern = const RegExp(@"^\[([^\]]+)\]");
 final RegExp RulePattern = const RegExp(@"\s*([^: ]*)\s*:(.*)");
-final RegExp PrefixPattern = const RegExp(@"^\s*prefix\s+([\w\_\.\-\/]+)\s*$");
 
 // TODO(whesse): Implement configuration_info library that contains data
 // structures for test configuration, including Section.
 class Section {
   BooleanExpression condition;
   List<TestRule> testRules;
 
   Section.always() : condition = null, testRules = new List<TestRule>();
   Section(this.condition) : testRules = new List<TestRule>();
 
@@ skipping 24 matching lines @@
 void ReadConfigurationInto(path, sections, onDone) {
   File file = new File(path);
   if (!file.existsSync()) {
     throw new Exception('Cannot find test status file $path');
   }
   InputStream file_stream = file.openInputStream();
   StringInputStream lines = new StringInputStream(file_stream);
 
   Section current = new Section.always();
   sections.add(current);
-  String prefix = "";
 
   lines.onLine = () {
     String line;
     while ((line = lines.readLine()) != null) {
       Match match = StripComment.firstMatch(line);
       line = (match == null) ? "" : match[0];
       line = line.trim();
       if (line.isEmpty()) continue;
 
       match = HeaderPattern.firstMatch(line);
@@ skipping 11 matching lines @@
         String name = match[1].trim();
         // TODO(whesse): Handle test names ending in a wildcard (*).
         String expression_string = match[2].trim();
         List<String> tokens = new Tokenizer(expression_string).tokenize();
         SetExpression expression =
             new ExpressionParser(new Scanner(tokens)).parseSetExpression();
         current.testRules.add(new TestRule(name, expression));
         continue;
       }
 
-      match = PrefixPattern.firstMatch(line);
-      if (match != null) {
-        prefix = match[1];
-        continue;
-      }
-
       print("unmatched line: $line");
     }
   };
 
   lines.onClosed = () {
     onDone();
   };
 }
 
 
@@ skipping 90 matching lines @@
         }
         regExps[i] = regExp;
       }
       _keyToRegExps[key] = regExps;
     });
 
     _regExpCache = null;
     _preprocessed = true;
   }
 }