Refactor removeRange.

sdk/lib/_collection_dev/list.dart

Index: sdk/lib/_collection_dev/list.dart
diff --git a/sdk/lib/_collection_dev/list.dart b/sdk/lib/_collection_dev/list.dart
index ed01c1482f96867f0de47cf6beea0c2cc61aaef7..9ef466855d0b7777a2ac52d2ce8ae5463ada3d8f 100644
--- a/sdk/lib/_collection_dev/list.dart
+++ b/sdk/lib/_collection_dev/list.dart
@@ -70,7 +70,7 @@ abstract class FixedLengthListMixin<E>  {
         "Cannot remove from a fixed-length list");
   }
 
-  void removeRange(int start, int length) {
+  void removeRange(int start, int end) {
     throw new UnsupportedError(
         "Cannot remove from a fixed-length list");
   }
@@ -165,7 +165,7 @@ abstract class UnmodifiableListMixin<E> {
         "Cannot modify an unmodifiable list");
   }
 
-  void removeRange(int start, int length) {
+  void removeRange(int start, int end) {
     throw new UnsupportedError(
         "Cannot remove from an unmodifiable list");
   }