Implement BluetoothRemoteGattCharacteristicWin::StartNotifySession and related unit tests

device/bluetooth/bluetooth_task_manager_win.h

Index: device/bluetooth/bluetooth_task_manager_win.h
diff --git a/device/bluetooth/bluetooth_task_manager_win.h b/device/bluetooth/bluetooth_task_manager_win.h
index c8356a8a025ae234872b030dff8f759b65ba4fe5..0c640a77f37bcafabb025262d70ddb77d1b459e0 100644
--- a/device/bluetooth/bluetooth_task_manager_win.h
+++ b/device/bluetooth/bluetooth_task_manager_win.h
@@ -99,8 +99,6 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothTaskManagerWin
      // discovery session, the "friendly" name may initially be "unknown" before
      // the actual name is retrieved in subsequent poll events.
      virtual void DevicesPolled(const ScopedVector<DeviceState>& devices) {}
-     virtual void OnAttemptReadGattCharacteristic() {}
-     virtual void OnAttemptWriteGattCharacteristic() {}
   };
 
   explicit BluetoothTaskManagerWin(
@@ -135,6 +133,9 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothTaskManagerWin
   typedef base::Callback<void(scoped_ptr<BTH_LE_GATT_CHARACTERISTIC_VALUE>,
                               HRESULT)>
       ReadGattCharacteristicValueCallback;
+  typedef base::Callback<void(scoped_ptr<std::vector<uint8_t>>)>
+      GattCharacteristicValueChangedCallback;
+  typedef base::Callback<void(PVOID, HRESULT)> GattEventRegistrationCallback;
 
   // Get all included characteristics of a given service. The service is
   // uniquely identified by its |uuid| and |attribute_handle| with service
@@ -170,6 +171,22 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothTaskManagerWin
       const std::vector<uint8_t>& new_value,
       const HResultCallback& callback);
 
+  // Post a task to register to receive value changed notifications from
+  // |characteristic| in service with |service_path|. |ccc_descriptor| is the
+  // Client Characteristic Configuration descriptor. |registered_callback| is
+  // the function to be invoked if the event occured. The operation result is
+  // returned asynchronously through |callback|.
+  void PostRegisterGattCharacteristicValueChangedEvent(
+      const base::FilePath& service_path,
+      const PBTH_LE_GATT_CHARACTERISTIC characteristic,
+      const PBTH_LE_GATT_DESCRIPTOR ccc_descriptor,
+      const GattEventRegistrationCallback& callback,
+      const GattCharacteristicValueChangedCallback& registered_callback);
+
+  // Post a task to unregister from value change notifications. |event_handle|
+  // was returned by PostRegisterGattCharacteristicValueChangedEvent.
+  void PostUnregisterGattCharacteristicValueChangedEvent(PVOID event_handle);
+
  private:
   friend class base::RefCountedThreadSafe<BluetoothTaskManagerWin>;
   friend class BluetoothTaskManagerWinTest;
@@ -278,6 +295,13 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothTaskManagerWin
                                     BTH_LE_GATT_CHARACTERISTIC characteristic,
                                     std::vector<uint8_t> new_value,
                                     const HResultCallback& callback);
+  void RegisterGattCharacteristicValueChangedEvent(
+      base::FilePath service_path,
+      BTH_LE_GATT_CHARACTERISTIC characteristic,
+      BTH_LE_GATT_DESCRIPTOR ccc_descriptor,
+      const GattEventRegistrationCallback& callback,
+      const GattCharacteristicValueChangedCallback& registered_callback);
+  void UnregisterGattCharacteristicValueChangedEvent(PVOID event_handle);
 
   // UI task runner reference.
   scoped_refptr<base::SequencedTaskRunner> ui_task_runner_;