Make includeAncestors match a separate method.

tools/dom/src/EventStreamProvider.dart

Index: tools/dom/src/EventStreamProvider.dart
diff --git a/tools/dom/src/EventStreamProvider.dart b/tools/dom/src/EventStreamProvider.dart
index a4ad4c0ff32f57134dd44ca4db26fb86b00a614c..8cced87ccd3ce5855c3a969147b056a585dfb7f7 100644
--- a/tools/dom/src/EventStreamProvider.dart
+++ b/tools/dom/src/EventStreamProvider.dart
@@ -52,7 +52,7 @@ class _ElementEventStreamImpl<T extends Event> extends _EventStream<T>
       super(target, eventType, useCapture);
 
   Stream<T> matches(String selector) =>
-      this.where((event) => event.target.matches(selector, true));
+      this.where((event) => event.target.matchesWithAncestors(selector));
 }
 
 /**
@@ -74,7 +74,7 @@ class _ElementListEventStreamImpl<T extends Event> extends Stream<T>
   }
 
   Stream<T> matches(String selector) =>
-      this.where((event) => event.target.matches(selector, true));
+      this.where((event) => event.target.matchesWIthAncestors(selector));
 
   // Delegate all regular Stream behavor to our wrapped Stream.
   StreamSubscription<T> listen(void onData(T event),