Turn on Polymer TodoMVC tests on Dart buildbots

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 947 matching lines @@
       String scriptPath = (compiler == 'none') ?
           dartWrapperFilename : compiledDartWrapperFilename;
       scriptPath = _createUrlPathFromFile(new Path(scriptPath));
 
       // Create the HTML file for the test.
       RandomAccessFile htmlTest =
           new File(htmlPath).openSync(mode: FileMode.WRITE);
       String content = null;
       Path dir = filePath.directoryPath;
       String nameNoExt = filePath.filenameWithoutExtension;
+
       Path pngPath = dir.append('$nameNoExt.png');
       Path txtPath = dir.append('$nameNoExt.txt');
+      Path customHtmlPath = dir.append('$nameNoExt.html');
       Path expectedOutput = null;
-      if (new File(pngPath.toNativePath()).existsSync()) {
-        expectedOutput = pngPath;
-        content = getHtmlLayoutContents(scriptType, new Path("$scriptPath"));
-      } else if (new File(txtPath.toNativePath()).existsSync()) {
-        expectedOutput = txtPath;
-        content = getHtmlLayoutContents(scriptType, new Path("$scriptPath"));
+
+      if (new File(customHtmlPath.toNativePath()).existsSync()) {
+        // Use existing HTML document if available.
+        htmlPath = customHtmlPath.toNativePath();
       } else {
-        content = getHtmlContents(filename, scriptType,
-            new Path("$scriptPath"));
+        if (new File(pngPath.toNativePath()).existsSync()) {
+          expectedOutput = pngPath;
+          content = getHtmlLayoutContents(scriptType, new Path("$scriptPath"));
+        } else if (new File(txtPath.toNativePath()).existsSync()) {
+          expectedOutput = txtPath;
+          content = getHtmlLayoutContents(scriptType, new Path("$scriptPath"));
+        } else {
+          content = getHtmlContents(filename, scriptType,
+              new Path("$scriptPath"));
+        }
+        htmlTest.writeStringSync(content);
+        htmlTest.closeSync();
       }
-      htmlTest.writeStringSync(content);
-      htmlTest.closeSync();
 
       // Construct the command(s) that compile all the inputs needed by the
       // browser test. For running Dart in DRT, this will be noop commands.
       List<Command> commands = [];
       if (compiler != 'none') {
         commands.add(_compileCommand(
             dartWrapperFilename, compiledDartWrapperFilename,
             compiler, tempDir, vmOptions, optionsFromFile));
       }
 
@@ skipping 971 matching lines @@
  * $pass tests are expected to pass
  * $failOk tests are expected to fail that we won't fix
  * $fail tests are expected to fail that we should fix
  * $crash tests are expected to crash that we should fix
  * $timeout tests are allowed to timeout
  * $compileErrorSkip tests are skipped on browsers due to compile-time error
 """;
     print(report);
    }
 }