Migrate all LayoutTests/dart/dom to main repo.

client/tests/client/dom/XHRTest.dart

Index: client/tests/client/dom/XHRTest.dart
diff --git a/client/tests/client/dom/XHRTest.dart b/client/tests/client/dom/XHRTest.dart
new file mode 100644
index 0000000000000000000000000000000000000000..d89bcd48f26e2a40fc77a0dc08d9adb45148ae80
--- /dev/null
+++ b/client/tests/client/dom/XHRTest.dart
@@ -0,0 +1,19 @@
+#library('XHRTest');
+#import('../../../testing/unittest/unittest.dart');
+#import('dart:dom');
+
+main() {
+  forLayoutTests();
+  asyncTest('XHR', 1, () {
+    XMLHttpRequest xhr = new XMLHttpRequest();
+    xhr.open('GET', 'XHR.html', true);
+    xhr.addEventListener('readystatechange', (event) {
+      if (xhr.readyState == 4)
+        if (xhr.status == 200 || xhr.status == 0) {
+          Expect.notEquals(-1, xhr.responseText.indexOf('XHR.dart', 0));
+          callbackDone();
+        }
+    }, true);
+    xhr.send();
+  });
+}