Further code review changes for issue 8341027.

client/html/src/DocumentFragmentWrappingImplementation.dart

Index: client/html/src/DocumentFragmentWrappingImplementation.dart
diff --git a/client/html/src/DocumentFragmentWrappingImplementation.dart b/client/html/src/DocumentFragmentWrappingImplementation.dart
index 54b9644270c644e46ebb47b3d345c6e82aae628b..4b7667d42feeb821d61155ab9cb2536aa0f5914a 100644
--- a/client/html/src/DocumentFragmentWrappingImplementation.dart
+++ b/client/html/src/DocumentFragmentWrappingImplementation.dart
@@ -108,8 +108,17 @@ class FilteredElementList implements ElementList {
 
 class EmptyStyleDeclaration extends CSSStyleDeclarationWrappingImplementation {
   // This can't call super(), since that's a factory constructor
-  EmptyStyleDeclaration()
-    : super._wrap(dom.document.createElement('div').style);
+  const EmptyStyleDeclaration() : super._empty();
+
+  String get cssText() => "";
+  int get length() => 0;
+  CSSRule get parentRule() => null;
+  CSSValue getPropertyCSSValue(String propertyName) => null;	
+  String getPropertyPriority(String propertyName) => "";	
+  String getPropertyShorthand(String propertyName) => null;	
+  String getPropertyValue(String propertyName) => null;	
+  bool isPropertyImplicit(String propertyName) => false;	
+  String item(int index) => "";
 
   void set cssText(String value) {
     throw new UnsupportedOperationException(
@@ -138,6 +147,8 @@ class EmptyClientRect implements ClientRect {
 
 class DocumentFragmentWrappingImplementation extends NodeWrappingImplementation implements DocumentFragment {
   ElementList _elements;
+  CSSStyleDeclaration _style;
+  ClientRect _clientRect;
 
   DocumentFragmentWrappingImplementation._wrap(ptr) : super._wrap(ptr) {}
 
@@ -228,6 +239,16 @@ class DocumentFragmentWrappingImplementation extends NodeWrappingImplementation
   ElementList queryAll(String selectors) =>
     LevelDom.wrapElementList(_ptr.querySelectorAll(selectors));
 
+  CSSStyleDeclaration get style() {
+    if (_style == null) _style = const EmptyStyleDeclaration();
+    return _style;
+  }
+
+  ClientRect getBoundingClientRect() {
+    if (_clientRect == null) _clientRect = new EmptyClientRect();
+    return _clientRect;
+  }
+
   // If we can come up with a semi-reasonable default value for an Element
   // getter, we'll use it. In general, these return the same values as an
   // element that has no parent.
@@ -263,8 +284,6 @@ class DocumentFragmentWrappingImplementation extends NodeWrappingImplementation
   // Issue 174: this should be a const set.
   Set<String> get classes() => new Set<String>();
   Map<String, String> get dataAttributes() => const {};
-  CSSStyleDeclaration get style() => new EmptyStyleDeclaration();
-  ClientRect getBoundingClientRect() => new EmptyClientRect();
   List<ClientRect> getClientRects() => const [];
   bool matchesSelector([String selectors]) => false;