Add ByteArray interface and provide internal and external implementations.

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index fabeaf7b2c025f864b7f85d978691eac89617447..f690aa871c9d2f884e49c10eff4aa45796f8b35b 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -1660,6 +1660,24 @@ DART_EXPORT Dart_Handle Dart_ListSetAsBytes(Dart_Handle list,
 }
 
 
+// --- Byte Arrays ---
+
+
+DART_EXPORT bool Dart_IsByteArray(Dart_Handle object) {
+  DARTSCOPE(Isolate::Current());
+  const Object& obj = Object::Handle(Api::UnwrapHandle(object));
+  return obj.IsByteArray();
+}
+
+
+DART_EXPORT Dart_Handle Dart_NewByteArray(intptr_t length) {
+  DARTSCOPE(Isolate::Current());
+  const InternalByteArray& obj =
+      InternalByteArray::Handle(InternalByteArray::New(length));
+  return Api::NewLocalHandle(obj);
+}
+
+
 // --- Closures ---