Support for pixel layout tests.

utils/testrunner/layout_test_runner.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.
+
+// The filters must be set by the caller that #sources this file.
+List includeFilters;
+List excludeFilters;
+
+class LayoutTestConfiguration extends unittest.Configuration {
+  get autoStart => false;
+  void onTestResult(unittest.TestCase testCase) {
+    window.postMessage('done', '*'); // Unblock DRT
+  }
+}
+
+filterTest(t) {
+  var name = t.description.replaceAll("###", " ");
+  if (includeFilters.length > 0) {
+    for (var f in includeFilters) {
+      if (name.indexOf(f) >= 0) return true;
+    }
+    return false;
+  } else if (excludeFilters.length > 0) {
+    for (var f in excludeFilters) {
+      if (name.indexOf(f) >= 0) return false;
+    }
+    return true;
+  } else {
+    return true;
+  }
+}
+
+runTests(testMain) {
+  unittest.groupSep = '###';
+  unittest.configure(new LayoutTestConfiguration());
+
+  // Create the set of test cases.
+  unittest.group('', testMain);
+
+  // Do any user-specified test filtering.
+  unittest.filterTests(filterTest);
+
+  // Filter to the test number in the search query.
+  var testNum = int.parse(window.location.search.substring(6));
+  if (testNum < 0 || testNum >= unittest.testCases.length) {
+    print('#TEST NONEXISTENT');
+    window.postMessage('done', '*'); // Unblock DRT
+  } else {
+    var name = unittest.testCases[testNum].description;
+    print('#TEST $name');
+    unittest.filterTests(name);
+    // Run the test.
+    print('Tests - ${unittest.testCases.length}');
+    unittest.runTests();
+  }
+}