Remove insertRange.

sdk/lib/html/html_common/filtered_element_list.dart

Index: sdk/lib/html/html_common/filtered_element_list.dart
diff --git a/sdk/lib/html/html_common/filtered_element_list.dart b/sdk/lib/html/html_common/filtered_element_list.dart
index 33bf357a0d1f3040d8e75ac0a5717b48f082244c..cad661e7b0ae1dc01b37036b1d9e043a4b98676d 100644
--- a/sdk/lib/html/html_common/filtered_element_list.dart
+++ b/sdk/lib/html/html_common/filtered_element_list.dart
@@ -46,7 +46,7 @@ class FilteredElementList extends ListBase<Element> {
       throw new ArgumentError("Invalid list length");
     }
 
-    removeRange(newLength, len - newLength);
+    removeRange(newLength, len);
   }
 
   String join([String separator = ""]) => _filtered.join(separator);
@@ -76,12 +76,8 @@ class FilteredElementList extends ListBase<Element> {
     throw new UnimplementedError();
   }
 
-  void removeRange(int start, int rangeLength) {
-    _filtered.sublist(start, start + rangeLength).forEach((el) => el.remove());
-  }
-
-  void insertRange(int start, int rangeLength, [initialValue = null]) {
-    throw new UnimplementedError();
+  void removeRange(int start, int end) {
+    _filtered.sublist(start, end).forEach((el) => el.remove());
   }
 
   void clear() {