bluetooth: Blink side implementation of getPrimaryService

Source/modules/bluetooth/BluetoothGATTService.cpp

+// Copyright 2015 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.
+
+#include "config.h"
+#include "modules/bluetooth/BluetoothGATTService.h"
+
+#include "public/platform/modules/bluetooth/WebBluetoothGATTRemoteServer.h"
+#include "wtf/OwnPtr.h"
+
+namespace blink {
+
+BluetoothGATTService::BluetoothGATTService(const WebBluetoothGATTService& webService)
+    : m_webService(webService)
+{
+}
+
+BluetoothGATTService* BluetoothGATTService::take(ScriptPromiseResolver*, WebBluetoothGATTService* webServiceRawPointer)
+{
+    if (!webServiceRawPointer) {
+        return nullptr;
+    }
+    OwnPtr<WebBluetoothGATTService> webService = adoptPtr(webServiceRawPointer);

[haraken, 2015/05/24 00:13:50]

We should avoid the adoptPtr(raw_pointer) pattern since it is error-prone.
adoptPtr needs to be used in the adoptPtr(new WebBluetoothGATTService) pattern.
See the comment below as well.

[yhirano, 2015/05/25 02:30:00]

To: haraken@
Yeah, I agree that this is ugly, but this is enforced by CallbackPromiseAdapter
design. Please see its class comment.

[haraken, 2015/05/26 11:45:33]

I'm curious why we can't make CallbackPromiseAdapter hold an OwnPtr to
BluetoothGATTService. That OwnPtr could be cleared when the
CallbackPromiseAdapter disposes the BluetoothGATTService...?

+    return new BluetoothGATTService(*webService);
+}
+
+void BluetoothGATTService::dispose(WebBluetoothGATTService* webService)
+{
+    delete webService;

[haraken, 2015/05/24 00:13:51]

Manually deleting an object looks terrible :)

Can you make BluetoothGATTService hold an OwnPtr<WebBluetoothGATTService>? Then
you can just call m_webService.clear() here.

[yhirano, 2015/05/25 02:30:00]

To: haraken@
ditto

+}
+
+} // namespace blink