Re-enable Object.observe and add enforcement for security invariants.

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #include <cmath>  // For isnan.
 #include "../include/v8-debug.h"
 #include "../include/v8-profiler.h"
@@ skipping 3549 matching lines @@
   ENTER_V8(isolate);
   i::Handle<i::JSObject> self = Utils::OpenHandle(this);
   EXCEPTION_PREAMBLE(isolate);
   i::Handle<i::JSObject> result = isolate->factory()->CopyJSObject(self);
   has_pending_exception = result.is_null();
   EXCEPTION_BAILOUT_CHECK(isolate, Local<Object>());
   return Utils::ToLocal(result);
 }
 
 
-static i::Context* GetCreationContext(i::JSObject* object) {
-  i::Object* constructor = object->map()->constructor();
-  i::JSFunction* function;
-  if (!constructor->IsJSFunction()) {
-    // Functions have null as a constructor,
-    // but any JSFunction knows its context immediately.
-    ASSERT(object->IsJSFunction());
-    function = i::JSFunction::cast(object);
-  } else {
-    function = i::JSFunction::cast(constructor);
-  }
-  return function->context()->native_context();
-}
-
-
 Local<v8::Context> v8::Object::CreationContext() {
   i::Isolate* isolate = Utils::OpenHandle(this)->GetIsolate();
   ON_BAILOUT(isolate,
              "v8::Object::CreationContext()", return Local<v8::Context>());
   ENTER_V8(isolate);
   i::Handle<i::JSObject> self = Utils::OpenHandle(this);
-  i::Context* context = GetCreationContext(*self);
+  i::Context* context = self->GetCreationContext();
   return Utils::ToLocal(i::Handle<i::Context>(context));
 }
 
 
 int v8::Object::GetIdentityHash() {
   i::Isolate* isolate = Utils::OpenHandle(this)->GetIsolate();
   ON_BAILOUT(isolate, "v8::Object::GetIdentityHash()", return 0);
   ENTER_V8(isolate);
   i::HandleScope scope(isolate);
   i::Handle<i::JSObject> self = Utils::OpenHandle(this);
@@ skipping 3980 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal