Use ByteArray's native for Socket and File.

runtime/lib/byte_array.cc

Index: runtime/lib/byte_array.cc
===================================================================
--- runtime/lib/byte_array.cc	(revision 3698)
+++ runtime/lib/byte_array.cc	(working copy)
@@ -30,6 +30,35 @@
 }
 
 
+DEFINE_NATIVE_ENTRY(ByteArray_setRange, 5) {
+  ByteArray& dst = ByteArray::CheckedHandle(arguments->At(0));
+  GET_NATIVE_ARGUMENT(ByteArray, src, arguments->At(1));
+  GET_NATIVE_ARGUMENT(Smi, src_start, arguments->At(2));
+  GET_NATIVE_ARGUMENT(Smi, dst_start, arguments->At(3));
+  GET_NATIVE_ARGUMENT(Smi, count, arguments->At(4));
+  if (count.Value() < 0) {
+    GrowableArray<const Object*> args;
+    Exceptions::ThrowByType(Exceptions::kIllegalArgument, args);
+  }
+  if (!dart::Utils::RangeCheck(src_start.Value(),
+                               count.Value(),
+                               src.Length())) {
+    GrowableArray<const Object*> arguments;
+    arguments.Add(&src_start);
+    Exceptions::ThrowByType(Exceptions::kIndexOutOfRange, arguments);
+  }
+  if (!dart::Utils::RangeCheck(dst_start.Value(),
+                               count.Value(),
+                               dst.Length())) {
+    GrowableArray<const Object*> arguments;
+    arguments.Add(&dst_start);
+    Exceptions::ThrowByType(Exceptions::kIndexOutOfRange, arguments);
+  }
+  ByteArray::Copy(
+      dst, dst_start.Value(), src, src_start.Value(), count.Value());
+}
+
+
 static void RangeCheck(const ByteArray& array, const Smi& index,
                        intptr_t num_bytes) {
   if ((index.Value() < 0) || ((index.Value() + num_bytes) > array.Length())) {