Strip unused functionality from dart:html and fix strong mode errors. Switch from blacklisting pure…

tools/dom/src/EventStreamProvider.dart

 // Copyright (c) 2013, 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.
 
 part of html;
 
 /**
  * A factory to expose DOM events as Streams.
  */
 class EventStreamProvider<T extends Event> {
@@ skipping 58 matching lines @@
    *
    * This may be used to capture DOM events:
    *
    *     Element.keyDownEvent._forElementList(element, useCapture: true).listen(...);
    *
    * See also:
    *
    * [addEventListener](http://docs.webplatform.org/wiki/dom/methods/addEventListener)
    */
   ElementStream<T> _forElementList(ElementList e, {bool useCapture: false}) {
-    return new _ElementListEventStreamImpl(e, _eventType, useCapture);
+    return new _ElementListEventStreamImpl<T>(e, _eventType, useCapture);
   }
 
   /**
    * Gets the type of the event which this would listen for on the specified
    * event target.
    *
    * The target is necessary because some browsers may use different event names
    * for the same purpose and the target allows differentiating browser support.
    */
   String getEventType(EventTarget target) {
@@ skipping 197 matching lines @@
       _target.addEventListener(_eventType, _onData, _useCapture);
     }
   }
 
   void _unlisten() {
     if (_onData != null) {
       _target.removeEventListener(_eventType, _onData, _useCapture);
     }
   }
 
-  Future asFuture([var futureValue]) {
+  Future/*<E>*/ asFuture/*<E>*/([var/*=E*/ futureValue]) {
     // We just need a future that will never succeed or fail.
-    Completer completer = new Completer();
+    var completer = new Completer/*<E>*/();
     return completer.future;
   }
 }
 
 /**
  * A stream of custom events, which enables the user to "fire" (add) their own
  * custom events to a stream.
  */
 abstract class CustomStream<T extends Event> implements Stream<T> {
   /**
@@ skipping 127 matching lines @@
     return new _ElementListEventStreamImpl<T>(e, _eventTypeGetter(e), useCapture);
   }
 
   String getEventType(EventTarget target) {
     return _eventTypeGetter(target);
   }
 
   String get _eventType =>
       throw new UnsupportedError('Access type through getEventType method.');
 }