Use Point<num> in dart:html for strong mode

tools/dom/templates/html/dart2js/impl_MouseEvent.darttemplate

Index: tools/dom/templates/html/dart2js/impl_MouseEvent.darttemplate
diff --git a/tools/dom/templates/html/dart2js/impl_MouseEvent.darttemplate b/tools/dom/templates/html/dart2js/impl_MouseEvent.darttemplate
index 8077fb006f0070499148393419aaa87e22009cdb..f5b7e1b7a9c37904cb8cb367d7fc493ac7c999e0 100644
--- a/tools/dom/templates/html/dart2js/impl_MouseEvent.darttemplate
+++ b/tools/dom/templates/html/dart2js/impl_MouseEvent.darttemplate
@@ -24,14 +24,14 @@ $!MEMBERS
 
   @DomName('MouseEvent.clientX')
   @DomName('MouseEvent.clientY')
-  Point get client => new Point(_clientX, _clientY);
+  Point get client => new Point/*<num>*/(_clientX, _clientY);
 
   @DomName('MouseEvent.movementX')
   @DomName('MouseEvent.movementY')
   @SupportedBrowser(SupportedBrowser.CHROME)
   @SupportedBrowser(SupportedBrowser.FIREFOX)
   @Experimental()
-  Point get movement => new Point(_movementX, _movementY);
+  Point get movement => new Point/*<num>*/(_movementX, _movementY);
 
   /**
    * The coordinates of the mouse pointer in target node coordinates.
@@ -44,7 +44,7 @@ $!MEMBERS
     if (JS('bool', '!!#.offsetX', this)) {
       var x = JS('int', '#.offsetX', this);
       var y = JS('int', '#.offsetY', this);
-      return new Point(x, y);
+      return new Point/*<num>*/(x, y);
     } else {
       // Firefox does not support offsetX.
       if (!(this.target is Element)) {
@@ -53,19 +53,19 @@ $!MEMBERS
       }
       Element target = this.target;
       var point = (this.client - target.getBoundingClientRect().topLeft);
-      return new Point(point.x.toInt(), point.y.toInt());
+      return new Point/*<num>*/(point.x.toInt(), point.y.toInt());
     }
   }
 
   @DomName('MouseEvent.screenX')
   @DomName('MouseEvent.screenY')
-  Point get screen => new Point(_screenX, _screenY);
+  Point get screen => new Point/*<num>*/(_screenX, _screenY);
 
   @DomName('MouseEvent.layerX')
   @DomName('MouseEvent.layerY')
-  Point get layer => new Point(_layerX, _layerY);
+  Point get layer => new Point/*<num>*/(_layerX, _layerY);
 
   @DomName('MouseEvent.pageX')
   @DomName('MouseEvent.pageY')
-  Point get page => new Point(_pageX, _pageY);
+  Point get page => new Point/*<num>*/(_pageX, _pageY);
 }