Fix bluetooth callback function declaration

device/bluetooth/bluetooth_low_energy_win.h

 // 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.
 
 #ifndef DEVICE_BLUETOOTH_BLUETOOTH_LOW_ENERGY_WIN_H_
 #define DEVICE_BLUETOOTH_BLUETOOTH_LOW_ENERGY_WIN_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
 #include "base/optional.h"
 #include "device/bluetooth/bluetooth_export.h"
 #include "device/bluetooth/bluetooth_low_energy_defs_win.h"
 
 namespace device {
 namespace win {
 
+//
+// Callback function signature for Bluetooth GATT events. This fixes a bug in
+// the prototype in the Windows 10.0.10586 SDK which is missing the CALLBACK
+// modifier. This typedef should be used throughout Chromium except when casting

[scheib, 2016/09/12 19:28:16]

Would be nice to include the 'why' you mention in the change description,
"CALLBACK which can lead to stack mismatches ... A fixed
typedef needs to be used throughout Chromium to ensure consistent
stack cleanup", in this comment.

+// to the 'official' definition when calling Microsoft functions. This allows
+// Chromium to build with 10.0.10586 or later SDKs (with the fix) while doing
+// the correct thing.
+//
+typedef VOID(CALLBACK* PFNBLUETOOTH_GATT_EVENT_CALLBACK_CORRECTED)(
+    _In_ BTH_LE_GATT_EVENT_TYPE EventType,
+    _In_ PVOID EventOutParameter,
+    _In_opt_ PVOID Context);
+
 // Represents a device registry property value
 class DEVICE_BLUETOOTH_EXPORT DeviceRegistryPropertyValue {
  public:
   // Creates a property value instance, where |property_type| is one of REG_xxx
   // registry value type (e.g. REG_SZ, REG_DWORD), |value| is a byte array
   // containing the property value and |value_size| is the number of bytes in
   // |value|. Note the returned instance takes ownership of the bytes in
   // |value|.
   static std::unique_ptr<DeviceRegistryPropertyValue> Create(
       DWORD property_type,
@@ skipping 141 matching lines @@
   virtual HRESULT WriteCharacteristicValue(
       base::FilePath& service_path,
       const PBTH_LE_GATT_CHARACTERISTIC characteristic,
       PBTH_LE_GATT_CHARACTERISTIC_VALUE new_value);
 
   // Register GATT events of |event_type| in the service with service device
   // path |service_path|. |event_parameter| is the event's parameter. |callback|
   // is the function to be invoked if the event happened. |context| is the input
   // parameter to be given back through |callback|. |*out_handle| stores the
   // unique handle in OS for this registration.
-  virtual HRESULT RegisterGattEvents(base::FilePath& service_path,
-                                     BTH_LE_GATT_EVENT_TYPE event_type,
-                                     PVOID event_parameter,
-                                     PFNBLUETOOTH_GATT_EVENT_CALLBACK callback,
-                                     PVOID context,
-                                     BLUETOOTH_GATT_EVENT_HANDLE* out_handle);
+  virtual HRESULT RegisterGattEvents(
+      base::FilePath& service_path,
+      BTH_LE_GATT_EVENT_TYPE event_type,
+      PVOID event_parameter,
+      PFNBLUETOOTH_GATT_EVENT_CALLBACK_CORRECTED callback,
+      PVOID context,
+      BLUETOOTH_GATT_EVENT_HANDLE* out_handle);
   virtual HRESULT UnregisterGattEvent(BLUETOOTH_GATT_EVENT_HANDLE event_handle);
 
   // Writes |descriptor| value in service with service device path
   // |service_path| to |*new_value|.
   virtual HRESULT WriteDescriptorValue(base::FilePath& service_path,
                                        const PBTH_LE_GATT_DESCRIPTOR descriptor,
                                        PBTH_LE_GATT_DESCRIPTOR_VALUE new_value);
 
  protected:
   BluetoothLowEnergyWrapper();
   virtual ~BluetoothLowEnergyWrapper();
 };
 
 }  // namespace win
 }  // namespace device
 
 #endif  // DEVICE_BLUETOOTH_BLUETOOTH_LOW_ENERGY_WIN_H_