Implemented BluetoothAdapterWin::IsPresent().

device/bluetooth/bluetooth_adapter_win.h

Index: device/bluetooth/bluetooth_adapter_win.h
diff --git a/device/bluetooth/bluetooth_adapter_win.h b/device/bluetooth/bluetooth_adapter_win.h
index de76b18e8eb7719b0994d5c782dd90685655601f..0524bb73d5692aa089f3d90e456718afdf8a16f3 100644
--- a/device/bluetooth/bluetooth_adapter_win.h
+++ b/device/bluetooth/bluetooth_adapter_win.h
@@ -13,9 +13,11 @@
 namespace device {
 
 class BluetoothAdapterFactory;
+class BluetoothAdapterWinTest;
 class BluetoothDevice;
 
 class BluetoothAdapterWin : public BluetoothAdapter {
+ public:
   // BluetoothAdapter override
   virtual void AddObserver(BluetoothAdapter::Observer* observer) OVERRIDE;
   virtual void RemoveObserver(BluetoothAdapter::Observer* observer) OVERRIDE;
@@ -38,11 +40,23 @@ class BluetoothAdapterWin : public BluetoothAdapter {
       const BluetoothOutOfBandPairingDataCallback& callback,
       const ErrorCallback& error_callback) OVERRIDE;
 
+ protected:
+  BluetoothAdapterWin();
+  virtual ~BluetoothAdapterWin();
+
+  virtual void UpdateAdapterState();
+
  private:
   friend class device::BluetoothAdapterFactory;
+  friend class device::BluetoothAdapterWinTest;
 
-  BluetoothAdapterWin();
-  virtual ~BluetoothAdapterWin();
+  // Obtains the default adapter info (the first bluetooth radio info) and
+  // tracks future changes to it.
+  void TrackDefaultAdapter();
+
+  void PollAdapterState();
+
+  static const int kPollIntervalMs;
 
   // NOTE: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.