Optimize dartium dart:html bindings so real world application performance is acceptable. Improves d…

tools/dom/templates/html/impl/impl_Element.darttemplate

 // Copyright (c) 2012, 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 $LIBRARYNAME;
 
 class _ChildrenElementList extends ListBase<Element>
     implements NodeListWrapper {
   // Raw Element.
   final Element _element;
@@ skipping 1466 matching lines @@
   static bool _hasCorruptedAttributesAdditionalCheck(Element element) {
     return JS('bool', r'!(#.attributes instanceof NamedNodeMap)', element);
   }
 $else
 
   static var _namedNodeMap = js.context["NamedNodeMap"];
   static var _htmlCollection = js.context["HTMLCollection"];
   static var _nodeList = js.context["NodeList"];
 
   static bool _hasCorruptedAttributes(Element element) {
-    var attributes = unwrap_jso(element)["attributes"];
-    if (!attributes.instanceof(_namedNodeMap)) {
-      return true;
-    }
-    var childNodes = unwrap_jso(element.childNodes);
-    var length = childNodes["length"];
-    var lastChild = unwrap_jso(element.lastChild);
-    if (null != lastChild &&
-        lastChild != childNodes[length - 1]) {
-      return true;
-    }
-    var children = unwrap_jso(element._children);
-    if (null != children) { // On Safari, children can apparently be null.
-      if (!children.instanceof(_htmlCollection) ||
-          children.instanceof(_nodeList)) {
-        return true;
-      }
-    }
+    // We could support this method on Dartium but it does not seem worthwhile

[Alan Knight, 2016/03/25 21:39:09]

They can be corrupted in a way that doesn't show up with direct Dartium access,
but would show up if calling indirectly through JS Interop. I think what we need
to do is have this check be done by calling a JS function. I'll take a look at
that.

[Jacob, 2016/03/30 00:19:00]

I switched to a version of the cleaned up version you sent me offline that only
uses trusted Eleement properties and now all the tests pass.

+    // given Dartium is a development platform and the checked method are
+    // implemented with C++ natives that cannot be corrupted.
     return false;
   }
 
   /// A secondary check for corruption, needed on IE
   static bool _hasCorruptedAttributesAdditionalCheck(Element element) => false;
 $endif
 
+$if DART2JS
   static String _safeTagName(element) {
     String result = 'element tag unavailable';
     try {
       if (element.tagName is String) {
         result = element.tagName;
       }
     } catch (e) {}
     return result;
   }
+$else
+  static String _safeTagName(element) {
+    try {

[Alan Knight, 2016/03/25 21:39:09]

Don't we need an implementation of this for Dartium, even if it's just a pass
through. I think there's code that calls it.

[Jacob, 2016/03/30 00:19:00]

not sure I understand. this is an implementation for Dartium that uses the fact
that tagName cannot be corrupted.

+      // Safe as we plumb directly to a C++ native method.
+      return element.tagName;
+    } catch (e) {}
+    return 'element tag unavailable';
+  }
+$endif  
 
 $if DART2JS
   @DomName('Element.offsetParent')
   @DocsEditable()
   final Element offsetParent;
 
   @DomName('Element.offsetHeight')
   @DocsEditable()
   int get offsetHeight => JS('num', '#.offsetHeight', this).round();
 
@@ skipping 32 matching lines @@
   set scrollTop(int value) {
     JS("void", "#.scrollTop = #", this, value.round());
   }
 
   @DomName('Element.scrollWidth')
   @DocsEditable()
   int get scrollWidth => JS('num', '#.scrollWidth', this).round();
 
 $else
   // Need to explicitly delegate because Element is no longer abstract for Dartium.
-  bool get isContentEditable => _blink.BlinkHTMLElement.instance.isContentEditable_Getter_(unwrap_jso(this));
-  void click() => _blink.BlinkHTMLElement.instance.click_Callback_0_(unwrap_jso(this));
+  bool get isContentEditable => _blink.BlinkHTMLElement.instance.isContentEditable_Getter_(this);
+  void click() => _blink.BlinkHTMLElement.instance.click_Callback_0_(this);
 
   @DomName('Element.offsetParent')
   @DocsEditable()
-  Element get offsetParent => wrap_jso(_blink.BlinkElement.instance.offsetParent_Getter_(unwrap_jso(this)));
+  Element get offsetParent => _blink.BlinkElement.instance.offsetParent_Getter_(this);
 
   @DomName('Element.offsetHeight')
   @DocsEditable()
-  int get offsetHeight => _blink.BlinkElement.instance.offsetHeight_Getter_(unwrap_jso(this));
+  int get offsetHeight => _blink.BlinkElement.instance.offsetHeight_Getter_(this);
 
   @DomName('Element.offsetLeft')
   @DocsEditable()
-  int get offsetLeft => _blink.BlinkElement.instance.offsetLeft_Getter_(unwrap_jso(this));
+  int get offsetLeft => _blink.BlinkElement.instance.offsetLeft_Getter_(this);
 
   @DomName('Element.offsetTop')
   @DocsEditable()
-  int get offsetTop => _blink.BlinkElement.instance.offsetTop_Getter_(unwrap_jso(this));
+  int get offsetTop => _blink.BlinkElement.instance.offsetTop_Getter_(this);
 
   @DomName('Element.offsetWidth')
   @DocsEditable()
-  int get offsetWidth => _blink.BlinkElement.instance.offsetWidth_Getter_(unwrap_jso(this));
+  int get offsetWidth => _blink.BlinkElement.instance.offsetWidth_Getter_(this);
 
   @DomName('Element.scrollHeight')
   @DocsEditable()
-  int get scrollHeight => _blink.BlinkElement.instance.scrollHeight_Getter_(unwrap_jso(this)).round();
+  int get scrollHeight => _blink.BlinkElement.instance.scrollHeight_Getter_(this).round();
 
   @DomName('Element.scrollLeft')
   @DocsEditable()
-  int get scrollLeft => _blink.BlinkElement.instance.scrollLeft_Getter_(unwrap_jso(this)).round();
+  int get scrollLeft => _blink.BlinkElement.instance.scrollLeft_Getter_(this).round();
 
   @DomName('Element.scrollLeft')
   @DocsEditable()
-  set scrollLeft(int value) => _blink.BlinkElement.instance.scrollLeft_Setter_(unwrap_jso(this), value.round());
+  set scrollLeft(int value) => _blink.BlinkElement.instance.scrollLeft_Setter_(this, value.round());
 
   @DomName('Element.scrollTop')
   @DocsEditable()
-  int get scrollTop => _blink.BlinkElement.instance.scrollTop_Getter_(unwrap_jso(this)).round();
+  int get scrollTop => _blink.BlinkElement.instance.scrollTop_Getter_(this).round();
 
   @DomName('Element.scrollTop')
   @DocsEditable()
-  set scrollTop(int value) => _blink.BlinkElement.instance.scrollTop_Setter_(unwrap_jso(this), value.round());
+  set scrollTop(int value) => _blink.BlinkElement.instance.scrollTop_Setter_(this, value.round());
 
   @DomName('Element.scrollWidth')
   @DocsEditable()
-  int get scrollWidth => _blink.BlinkElement.instance.scrollWidth_Getter_(unwrap_jso(this)).round();
+  int get scrollWidth => _blink.BlinkElement.instance.scrollWidth_Getter_(this).round();
 $endif
 
 $!MEMBERS
 }
 
 
 class _ElementFactoryProvider {
 
   @DomName('Document.createElement')
 $if DART2JS
@@ skipping 27 matching lines @@
   const ScrollAlignment._internal(this._value);
   toString() => 'ScrollAlignment.$_value';
 
   /// Attempt to align the element to the top of the scrollable area.
   static const TOP = const ScrollAlignment._internal('TOP');
   /// Attempt to center the element in the scrollable area.
   static const CENTER = const ScrollAlignment._internal('CENTER');
   /// Attempt to align the element to the bottom of the scrollable area.
   static const BOTTOM = const ScrollAlignment._internal('BOTTOM');
 }