Introduce a PrototypeIterator class and use it for prototype access

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index d01d826e70ba69d5aa9cfc06e730a260fb67eb0a..f23221871247b3d277d510e9217fbd5db1aa55ff 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -36,6 +36,7 @@
 #include "src/profile-generator-inl.h"
 #include "src/property.h"
 #include "src/property-details.h"
+#include "src/prototype.h"
 #include "src/runtime.h"
 #include "src/runtime-profiler.h"
 #include "src/scanner-character-streams.h"
@@ -3223,8 +3224,8 @@ Local<Value> v8::Object::GetPrototype() {
   ON_BAILOUT(isolate, "v8::Object::GetPrototype()", return Local<v8::Value>());
   ENTER_V8(isolate);
   i::Handle<i::Object> self = Utils::OpenHandle(this);
-  i::Handle<i::Object> result(self->GetPrototype(isolate), isolate);
-  return Utils::ToLocal(result);
+  i::PrototypeIterator iter(isolate, self);
+  return Utils::ToLocal(i::PrototypeIterator::GetCurrent(iter));
 }