Revert of Reland: Geolocation: move from content/browser to device/

content/browser/geolocation/wifi_data_provider_manager.h

Index: content/browser/geolocation/wifi_data_provider_manager.h
diff --git a/content/browser/geolocation/wifi_data_provider_manager.h b/content/browser/geolocation/wifi_data_provider_manager.h
new file mode 100644
index 0000000000000000000000000000000000000000..652cf6437100be912ff0edbecbaaaec6aaca2b99
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+++ b/content/browser/geolocation/wifi_data_provider_manager.h
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+// 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_