Added support for layout render tests. These use expected values for the text render output from Du…

pkg/unittest/unittest.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.
 
 /**
  * A library for writing dart unit tests.
  *
  * To import this library, specify the relative path to
  * pkg/unittest/unittest.dart.
  *
@@ skipping 151 matching lines @@
  * Set the [Configuration] used by the unittest library. Returns any
  * previous configuration.
  * TODO: consider deprecating in favor of a setter now we have a getter.
  */
 Configuration configure(Configuration config) {
   Configuration _oldConfig = _config;
   _config = config;
   return _oldConfig;
 }
 
-void logMessage(String message) => _config.log(message);
+void logMessage(String message) => _config.logMessage(message);
 
 /**
  * Description text of the current test group. If multiple groups are nested,
  * this will contain all of their text concatenated.
  */
 String _currentGroup = '';
 
 /** Separator used between group names and test names. */
 String groupSep = ' ';
 
@@ skipping 681 matching lines @@
 }
 
 /** Enable a test by ID. */
 void enableTest(int testId) => _setTestEnabledState(testId, true);
 
 /** Disable a test by ID. */
 void disableTest(int testId) => _setTestEnabledState(testId, false);
 
 /** Signature for a test function. */
 typedef void TestFunction();