Add js api for hosted/pacakged apps to request notification authorization

chrome/renderer/extensions/callback_map.cc

+// 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.
+
+#include "base/logging.h"
+#include "chrome/renderer/extensions/callback_map.h"
+
+namespace extensions_v8_util {
+
+CallbackMap::CallbackMap()
+    : ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)) {}
+
+CallbackMap::~CallbackMap() {}
+
+// Extra data to be passed to MakeWeak/RemoveFromCallbackMap to know which entry
+// to remove from which map.
+struct CallbackMapData {
+  base::WeakPtr<CallbackMap> callback_map;
+  int key;
+};
+
+// Disposes of a callback function and its corresponding entry in the callback
+// map, if that callback map is still alive.
+static void RemoveFromCallbackMap(v8::Persistent<v8::Value> context,
+                                  void* data) {
+  CallbackMapData* callback_map_data = static_cast<CallbackMapData*>(data);
+  if (callback_map_data->callback_map)
+    callback_map_data->callback_map->Remove(callback_map_data->key);
+  delete callback_map_data;
+  context.Dispose();
+}
+
+void CallbackMap::Add(int key, v8::Local<v8::Function> callback_function) {
+  CallbackMapData* callback_map_data = new CallbackMapData();
+  callback_map_data->key = key;
+  callback_map_data->callback_map = weak_ptr_factory_.GetWeakPtr();
+  v8::Persistent<v8::Function> wrapper =
+      v8::Persistent<v8::Function>::New(callback_function);
+  map_[key] = wrapper;
+  wrapper.MakeWeak(callback_map_data, RemoveFromCallbackMap);
+}
+
+v8::Persistent<v8::Function> CallbackMap::Remove(int key) {
+  CallbackMap::Map::iterator i = map_.find(key);
+  if (i == map_.end())
+    return v8::Persistent<v8::Function>();
+  v8::Persistent<v8::Function> callback = i->second;
+  map_.erase(i);
+  return callback;
+}
+
+}  // namespace extensions_v8_util