Refactor List.setRange function.

runtime/lib/typeddata.dart

Index: runtime/lib/typeddata.dart
diff --git a/runtime/lib/typeddata.dart b/runtime/lib/typeddata.dart
index ff281ab7abd212c50c894cb87d6fa43497d62490..b7acbd2a992bcab525578d1eb548c873942a370b 100644
--- a/runtime/lib/typeddata.dart
+++ b/runtime/lib/typeddata.dart
@@ -568,10 +568,10 @@ abstract class _TypedListBase {
     return IterableMixinWorkaround.getRangeList(this, start, end);
   }
 
-  void setRange(int start, int length, List from, [int startFrom = 0]) {
-    if (!_setRange(start, length, from, startFrom)) {
+  void setRange(int start, int end, Iterable iterable, [int skipCount = 0]) {
+    if (!_setRange(start, end - start, iterable, skipCount)) {
       IterableMixinWorkaround.setRangeList(this, start,
-                                           length, from, startFrom);
+                                           end, iterable, skipCount);
     }
   }
 
@@ -585,7 +585,7 @@ abstract class _TypedListBase {
 
   // Internal utility methods.
 
-  bool _setRange(int start, int length, List from, startFrom)
+  bool _setRange(int start, int length, Iterable from, int startFrom)
       native "TypedData_setRange";
 }