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

runtime/lib/growable_array.dart

Index: runtime/lib/growable_array.dart
diff --git a/runtime/lib/growable_array.dart b/runtime/lib/growable_array.dart
index 5a1ba161ede5a24ecb34faf9dca1ae9334e9f79a..956a6ef61b8c5a308ee18676776ce19c71c536f0 100644
--- a/runtime/lib/growable_array.dart
+++ b/runtime/lib/growable_array.dart
@@ -8,10 +8,6 @@ class GrowableObjectArray<T> implements List<T> {
         "GrowableObjectArray can only be allocated by the VM");
   }
 
-  void copyFrom(List src, int srcStart, int dstStart, int count) {
-    Arrays.copy(src, srcStart, this, dstStart, count);
-  }
-
   void setRange(int start, int length, List<T> from, [int startFrom = 0]) {
     if (length < 0) {
       throw new IllegalArgumentException("negative length $length");