Dereference remote objects with native code

Previously we rely on the v8util.setDestructor to dereference the remote
objects in JavaScript, however as documented in V8, it is forbidden to
call V8 APIs in object's destructor (e.g. the weak callback), and doing
so would result in crashs.

This commit removes the JavaScript setDestructor method, and avoids
doing the dereference work with V8.

atom/common/api/remote_object_freer.h

@@ -0,0 +1,32 @@
+// Copyright (c) 2016 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_COMMON_API_REMOTE_OBJECT_FREER_H_
+#define ATOM_COMMON_API_REMOTE_OBJECT_FREER_H_
+
+#include "atom/common/api/object_life_monitor.h"
+
+namespace atom {
+
+class RemoteObjectFreer : public ObjectLifeMonitor {
+ public:
+  static void BindTo(
+      v8::Isolate* isolate, v8::Local<v8::Object> target, int object_id);
+
+ protected:
+  RemoteObjectFreer(
+      v8::Isolate* isolate, v8::Local<v8::Object> target, int object_id);
+  ~RemoteObjectFreer() override;
+
+  void RunDestructor() override;
+
+ private:
+  int object_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(RemoteObjectFreer);
+};
+
+}  // namespace atom
+
+#endif  // ATOM_COMMON_API_REMOTE_OBJECT_FREER_H_