(Second attempt at http://codereview.chromium.org/553069/show)...

chrome/browser/geolocation/wifi_data_provider_osx.h

Index: chrome/browser/geolocation/wifi_data_provider_osx.h
===================================================================
--- chrome/browser/geolocation/wifi_data_provider_osx.h	(revision 0)
+++ chrome/browser/geolocation/wifi_data_provider_osx.h	(revision 0)
@@ -0,0 +1,71 @@
+// Copyright 2008, Google Inc.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+//  1. Redistributions of source code must retain the above copyright notice,
+//     this list of conditions and the following disclaimer.
+//  2. Redistributions in binary form must reproduce the above copyright notice,
+//     this list of conditions and the following disclaimer in the documentation
+//     and/or other materials provided with the distribution.
+//  3. Neither the name of Google Inc. nor the names of its contributors may be
+//     used to endorse or promote products derived from this software without
+//     specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+// EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+// OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+// ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef GEARS_GEOLOCATION_WIFI_DATA_PROVIDER_OSX_H__
+#define GEARS_GEOLOCATION_WIFI_DATA_PROVIDER_OSX_H__
+
+#include "gears/base/common/common.h"
+#include "gears/base/common/event.h"
+#include "gears/base/common/mutex.h"
+#include "gears/base/common/thread.h"
+#include "gears/geolocation/device_data_provider.h"
+#include "gears/geolocation/osx_wifi.h"
+
+class OsxWifiDataProvider
+    : public WifiDataProviderImplBase,
+      public Thread {
+ public:
+  OsxWifiDataProvider();
+  virtual ~OsxWifiDataProvider();
+
+  // WifiDataProviderImplBase implementation.
+  virtual bool GetData(WifiData *data);
+
+ private:
+  // Thread implementation.
+  virtual void Run();
+  
+  void GetAccessPointData(WifiData::AccessPointDataSet *access_points);
+
+  // Context and function pointers for Apple80211 library.
+  WirelessContextPtr wifi_context_;
+  WirelessAttachFunction WirelessAttach_function_;
+  WirelessScanSplitFunction WirelessScanSplit_function_;
+  WirelessDetachFunction WirelessDetach_function_;
+
+  WifiData wifi_data_;
+  Mutex data_mutex_;
+
+  // Event signalled to shut down the thread that polls for wifi data.
+  Event stop_event_;
+
+  // Whether we've successfully completed a scan for WiFi data (or the polling
+  // thread has terminated early).
+  bool is_first_scan_complete_;
+
+  DISALLOW_EVIL_CONSTRUCTORS(OsxWifiDataProvider);
+};
+
+#endif  // GEARS_GEOLOCATION_WIFI_DATA_PROVIDER_OSX_H__