Relanding: Add js api for hosted/packaged apps to request notification authorization

chrome/renderer/weak_v8_function_map.h

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_RENDERER_WEAK_V8_FUNCTION_MAP_H_
+#define CHROME_RENDERER_WEAK_V8_FUNCTION_MAP_H_
+#pragma once
+
+#include <map>
+
+#include "base/compiler_specific.h"
+#include "base/memory/weak_ptr.h"
+#include "v8/include/v8.h"
+
+// This class lets you keep a mapping of integer to weak reference to a v8
+// function. The entry will automatically get removed from the map if the
+// function gets garbage collected.
+class WeakV8FunctionMap {
+ public:
+  WeakV8FunctionMap();
+  ~WeakV8FunctionMap();
+
+  // Adds |callback_function| to the map under |key|. The entry will be removed
+  // from the map when the function is about to be GCed.
+  void Add(int key, v8::Local<v8::Function> callback_function);
+
+  // Removes and returns a entry from the map for |key|. If there was no entry
+  // for |key|, the return value will return true for IsEmpty().
+  v8::Persistent<v8::Function> Remove(int key);
+
+ private:
+  typedef std::map<int, v8::Persistent<v8::Function> > Map;
+  Map map_;
+  base::WeakPtrFactory<WeakV8FunctionMap> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(WeakV8FunctionMap);
+};
+
+#endif  // CHROME_RENDERER_WEAK_V8_FUNCTION_MAP_H_