Remove List.copyFrom from VM and from tests. It was removed from the List interface in r941.

lib/dom/src/native_DOMImplementation.dart

Index: lib/dom/src/native_DOMImplementation.dart
diff --git a/lib/dom/src/native_DOMImplementation.dart b/lib/dom/src/native_DOMImplementation.dart
index 380b36af39237f028fb03f71c0a51d14f3160642..61f9a4b50299a661df69efc8467de21fe9f8395f 100644
--- a/lib/dom/src/native_DOMImplementation.dart
+++ b/lib/dom/src/native_DOMImplementation.dart
@@ -7,7 +7,7 @@ class _Utils {
     // FIXME: [possible optimization]: do not copy the array if Dart_IsArray is fine w/ it.
     final length = list.length;
     List result = new List(length);
-    result.copyFrom(list, 0, 0, length);
+    result.setRange(0, length, list);
     return result;
   }