Remove insertRange.

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

Index: tools/dom/templates/html/impl/impl_Element.darttemplate
diff --git a/tools/dom/templates/html/impl/impl_Element.darttemplate b/tools/dom/templates/html/impl/impl_Element.darttemplate
index a4872b370ce5ec3109e12c7761f95ace71cbb0f0..02ff65f2d26a5e681854247e510eaa53b06cf213 100644
--- a/tools/dom/templates/html/impl/impl_Element.darttemplate
+++ b/tools/dom/templates/html/impl/impl_Element.darttemplate
@@ -188,11 +188,7 @@ class _ChildrenElementList extends ListBase<Element> {
     _childElements.retainWhere(test);
   }
 
-  void removeRange(int start, int rangeLength) {
-    throw new UnimplementedError();
-  }
-
-  void insertRange(int start, int rangeLength, [initialValue = null]) {
+  void removeRange(int start, int end) {
     throw new UnimplementedError();
   }
 
@@ -314,11 +310,7 @@ class _FrozenElementList extends ListBase {
     throw new UnsupportedError('');
   }
 
-  void removeRange(int start, int rangeLength) {
-    throw new UnsupportedError('');
-  }
-
-  void insertRange(int start, int rangeLength, [initialValue = null]) {
+  void removeRange(int start, int end) {
     throw new UnsupportedError('');
   }