Cleaning up some unused code.

sdk/lib/html/dartium/html_dartium.dart

Index: sdk/lib/html/dartium/html_dartium.dart
diff --git a/sdk/lib/html/dartium/html_dartium.dart b/sdk/lib/html/dartium/html_dartium.dart
index d35e6394f08e93c539b24394dde84f42791faa4a..79edda29f51d858a50b36d132d3e3c6b3c9379a5 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -9426,24 +9426,6 @@ class _ElementCssClassSet extends CssClassSet {
   }
 }
 
-class _SimpleClientRect implements ClientRect {
-  final num left;
-  final num top;
-  final num width;
-  final num height;
-  num get right => left + width;
-  num get bottom => top + height;
-
-  const _SimpleClientRect(this.left, this.top, this.width, this.height);
-
-  bool operator ==(ClientRect other) {
-    return other != null && left == other.left && top == other.top
-        && width == other.width && height == other.height;
-  }
-
-  String toString() => "($left, $top, $width, $height)";
-}
-
 abstract class Element extends Node implements ElementTraversal {
 
   factory Element.html(String html) =>
@@ -28437,7 +28419,7 @@ abstract class _AttributeMap implements Map<String, String> {
 }
 
 /**
- * Wrapper to expose Element.attributes as a typed map.
+ * Wrapper to expose [Element.attributes] as a typed map.
  */
 class _ElementAttributeMap extends _AttributeMap {