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

content/browser/geolocation/wifi_data_provider.h

-// Copyright 2013 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 CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_H_
-#define CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_H_
-
-#include <set>
-
-#include "base/callback_forward.h"
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/single_thread_task_runner.h"
-#include "content/browser/geolocation/wifi_data.h"
-#include "content/common/content_export.h"
-
-namespace content {
-
-class CONTENT_EXPORT WifiDataProvider
-    : public base::RefCountedThreadSafe<WifiDataProvider> {
- public:
-  WifiDataProvider();
-
-  // Tells the provider to start looking for data. Callbacks will start
-  // receiving notifications after this call.
-  virtual void StartDataProvider() = 0;
-
-  // Tells the provider to stop looking for data. Callbacks will stop
-  // receiving notifications after this call.
-  virtual void StopDataProvider() = 0;
-
-  // Provides whatever data the provider has, which may be nothing. Return
-  // value indicates whether this is all the data the provider could ever
-  // obtain.
-  virtual bool GetData(WifiData* data) = 0;
-
-  typedef base::Closure WifiDataUpdateCallback;
-
-  void AddCallback(WifiDataUpdateCallback* callback);
-
-  bool RemoveCallback(WifiDataUpdateCallback* callback);
-
-  bool has_callbacks() const;
-
- protected:
-  friend class base::RefCountedThreadSafe<WifiDataProvider>;
-  virtual ~WifiDataProvider();
-
-  typedef std::set<WifiDataUpdateCallback*> CallbackSet;
-
-  // Runs all callbacks via a posted task, so we can unwind callstack here and
-  // avoid client reentrancy.
-  void RunCallbacks();
-
-  bool CalledOnClientThread() const;
-
-  scoped_refptr<base::SingleThreadTaskRunner> client_task_runner() const {
-    return client_task_runner_;
-  }
-
- private:
-  void DoRunCallbacks();
-
-  // The task runner for the client thread, all callbacks should run on it.
-  scoped_refptr<base::SingleThreadTaskRunner> client_task_runner_;
-
-  CallbackSet callbacks_;
-
-  DISALLOW_COPY_AND_ASSIGN(WifiDataProvider);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_GEOLOCATION_WIFI_DATA_PROVIDER_H_