Small-scale clean ups in test.dart, mainly around test_progress.

tools/testing/dart/test_suite.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.
 
 /**
  * Classes and methods for enumerating and preparing tests.
  *
  * This library includes:
  *
  * - Creating tests by listing all the Dart files in certain directories,
@@ skipping 1951 matching lines @@
       var csp = configuration['csp'] ? '-csp' : '';
       var sdk = configuration['use_sdk'] ? '-sdk' : '';
       var dirName = "${configuration['compiler']}"
           "$checked$strong$minified$csp$sdk";
       String generatedPath = "${TestUtils.buildDir(configuration)}"
           "/generated_compilations/$dirName";
       TestUtils.deleteDirectory(generatedPath);
     }
   }
 
-  static Path debugLogfile() {
-    return new Path(".debug.log");
-  }
+  static final debugLogFilePath = new Path(".debug.log");
 
-  static String flakyFileName() {
-    // If a flaky test did fail, infos about it (i.e. test name, stdin, stdout)
-    // will be written to this file. This is useful for the debugging of
-    // flaky tests.
-    // When running on a built bot, the file can be made visible in the
-    // waterfall UI.
-    return ".flaky.log";
-  }
+  /// If a flaky test did fail, infos about it (i.e. test name, stdin, stdout)
+  /// will be written to this file.
+  ///
+  /// This is useful for debugging flaky tests. When running on a buildbot, the
+  /// file can be made visible in the waterfall UI.
+  static const flakyFileName = ".flaky.log";
 
-  static String testOutcomeFileName() {
-    // If test.py was invoked with '--write-test-outcome-log it will write
-    // test outcomes to this file.
-    return ".test-outcome.log";
-  }
+  /// If test.py was invoked with '--write-test-outcome-log it will write
+  /// test outcomes to this file.
+  static const testOutcomeFileName = ".test-outcome.log";
 
   static void ensureExists(String filename, Map configuration) {
     if (!configuration['list'] && !existsCache.doesFileExist(filename)) {
       throw "'$filename' does not exist";
     }
   }
 
   static Path absolutePath(Path path) {
     if (!path.isAbsolute) {
       return currentWorkingDirectory.join(path);
@@ skipping 235 matching lines @@
       }
       if (path.length > WINDOWS_SHORTEN_PATH_LIMIT) {
         ++shortNameCounter;
         var pathEnd = path.substring(path.length - WINDOWS_PATH_END_LENGTH);
         path = "short${shortNameCounter}_$pathEnd";
       }
     }
     return path;
   }
 }