Issue #4692 - Rewrite `SetTimeout` facility to avoid `JsValuePtr` and `JsValueList`

src/JsEngineTransition.h

Index: src/JsEngineTransition.h
===================================================================
new file mode 100644
--- /dev/null
+++ b/src/JsEngineTransition.h
@@ -0,0 +1,31 @@
+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-2016 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * \file JsEngineTransition.h Assistance functions during transition away from `JsEnginePtr` etc.
+ */
+
+#if !defined(ADBLOCK_PLUS_JS_ENGINE_TRANSITION_H)
+#define ADBLOCK_PLUS_JS_ENGINE_TRANSITION_H
+
+#include <AdblockPlus/JsEngine.h>
+#include "JsEngineInternal.h"
+
+JsEngineInternal* ToInternal(AdblockPlus::JsEnginePtr p);
+JsEngineInternal* ToInternal(AdblockPlus::JsEngine* p);
+
+#endif