Adding event delegation.

tests/html/streams_test.dart

Index: tests/html/streams_test.dart
diff --git a/tests/html/streams_test.dart b/tests/html/streams_test.dart
index 6c75dfe206d64c4b25007495152e8e037e752691..3614421bb87a433046c8902d6dad39bbc65ef6bd 100644
--- a/tests/html/streams_test.dart
+++ b/tests/html/streams_test.dart
@@ -170,6 +170,31 @@ main() {
     expect(callCountOne, 1);
   });
 
+  test('forTargets', () {
+    var a = new StreamHelper();
+    var b = new StreamHelper();
+
+    var aTriggered = false;
+    var bTriggered = false;
+    Element.focusEvent.forTargets([a.element, b.element]).listen((e) {
+      if (e.target == a.element) {
+        aTriggered = true;
+      } else if (e.target == b.element) {
+        bTriggered = true;
+      } else {
+        expect(false, true, reason: 'Event for unrecognized element');
+      }
+    });
+
+    a.pulse();
+    expect(aTriggered, true);
+    expect(bTriggered, false);
+
+    b.pulse();
+    expect(aTriggered, true);
+    expect(bTriggered, true);
+  });
+
   var stream = new StreamHelper().stream;
   // Streams have had some type-checking issues, these tests just validate that
   // those are OK.