Reland 2:Geolocation: move from content/browser to device/

content/browser/geolocation/wifi_data_provider_manager.h

-// Copyright 2014 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.
-
-// A wifi data provider provides wifi data from the device that is used by a
-// NetworkLocationProvider to obtain a position fix. We use a singleton
-// instance of the wifi data provider manager, which is used by multiple
-// NetworkLocationProvider objects.
-//
-// This file provides WifiDataProviderManager, which provides static methods to
-// access the singleton instance. The singleton instance uses a private
-// implementation of WifiDataProvider to abstract across platforms and also to
-// allow mock providers to be used for testing.
-
-#ifndef CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_MANAGER_H_
-#define CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_MANAGER_H_
-
-#include <set>
-
-#include "base/bind.h"
-#include "base/callback.h"
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/strings/string16.h"
-#include "base/strings/string_util.h"
-#include "content/browser/geolocation/wifi_data.h"
-#include "content/common/content_export.h"
-
-namespace content {
-
-class WifiDataProvider;
-
-// A manager for wifi data providers.
-//
-// We use a singleton instance of this class which is shared by multiple network
-// location providers. These location providers access the instance through the
-// Register and Unregister methods.
-class CONTENT_EXPORT WifiDataProviderManager {
- public:
-  typedef WifiDataProvider* (*ImplFactoryFunction)(void);
-
-  // Sets the factory function which will be used by Register to create the
-  // implementation used by the singleton instance. This factory approach is
-  // used both to abstract accross platform-specific implementations and to
-  // inject mock implementations for testing.
-  static void SetFactoryForTesting(ImplFactoryFunction factory_function_in);
-
-  // Resets the factory function to the default.
-  static void ResetFactoryForTesting();
-
-  typedef base::Closure WifiDataUpdateCallback;
-
-  // Registers a callback, which will be run whenever new data is available.
-  // Instantiates the singleton if necessary, and always returns it.
-  static WifiDataProviderManager* Register(WifiDataUpdateCallback* callback);
-
-  // Removes a callback. If this is the last callback, deletes the singleton
-  // instance. Return value indicates success.
-  static bool Unregister(WifiDataUpdateCallback* callback);
-
-  // Provides whatever data the provider has, which may be nothing. Return
-  // value indicates whether this is all the data the provider could ever
-  // obtain.
-  bool GetData(WifiData* data);
-
- private:
-  // Private constructor and destructor, callers access singleton through
-  // Register and Unregister.
-  WifiDataProviderManager();
-  ~WifiDataProviderManager();
-
-  void AddCallback(WifiDataUpdateCallback* callback);
-  bool RemoveCallback(WifiDataUpdateCallback* callback);
-  bool has_callbacks() const;
-
-  void StartDataProvider();
-  void StopDataProvider();
-
-  static WifiDataProvider* DefaultFactoryFunction();
-
-  // The singleton-like instance of this class. (Not 'true' singleton, as it
-  // may go through multiple create/destroy/create cycles per process instance,
-  // e.g. when under test).
-  static WifiDataProviderManager* instance_;
-
-  // The factory function used to create the singleton instance.
-  static ImplFactoryFunction factory_function_;
-
-  // The internal implementation.
-  scoped_refptr<WifiDataProvider> impl_;
-
-  DISALLOW_COPY_AND_ASSIGN(WifiDataProviderManager);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_MANAGER_H_