http2: delete byte device without deleteLater

If we own the byte device we can just delete it directly when we are
done with it.

Change-Id: I9da99943ff61925f6f5416df403bcd747c2558d5
Reviewed-by: Dennis Oberst <dennis.oberst@qt.io>
Reviewed-by: Øystein Heskestad <oystein.heskestad@qt.io>
(cherry picked from commit 4bc878ff4fbacd39d4c0ed1e8e742fd18fa74fed)
Reviewed-by:  Alexey Edelev <alexey.edelev@qt.io>

src/network/access/qhttp2connection.cpp

@@ -277,7 +277,7 @@ void QHttp2Stream::sendDATA(QIODevice *device, bool endStream)
     qCDebug(qHttp2ConnectionLog, "[%p] starting sendDATA on stream %u, of device: %p",
             getConnection(), m_streamID, device);
     auto *byteDevice = QNonContiguousByteDeviceFactory::create(device);
-    connect(this, &QHttp2Stream::uploadFinished, byteDevice, &QObject::deleteLater);
+    m_owningByteDevice = true;
     byteDevice->setParent(this);
     m_uploadDevice = device;
     sendDATA(byteDevice, endStream);
@@ -423,6 +423,10 @@ void QHttp2Stream::finishSendDATA()
 
     disconnect(m_uploadByteDevice, nullptr, this, nullptr);
     m_uploadDevice = nullptr;
+    if (m_owningByteDevice) {
+        m_owningByteDevice = false;
+        delete m_uploadByteDevice;
+    }
     m_uploadByteDevice = nullptr;
     emit uploadFinished();
 }

src/network/access/qhttp2connection_p.h

@@ -196,6 +196,7 @@ private:
     State m_state = State::Idle;
     HPack::HttpHeader m_headers;
     bool m_isReserved = false;
+    bool m_owningByteDevice = false;
 
     friend tst_QHttp2Connection;
 };