winrt: Add media playback service

This introduces a MediaPlayer service based on the MFEngineEx API. Only
scene graph video rendering is supported at this time. The video renderer
control is abstracted in order to provide a base for future video nodes
which do not source their content from the MF engine.

[ChangeLog] Media player support was added to the winrt backend.

Change-Id: I8155a1030466ea352fad0a87d1ae97a88983760c
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>

src/plugins/winrt/qwinrtserviceplugin.cpp

@@ -43,9 +43,15 @@
 #include <QtCore/QFile>
 
 #include "qwinrtserviceplugin.h"
+#include "qwinrtmediaplayerservice.h"
+
+QT_USE_NAMESPACE
 
 QMediaService *QWinRTServicePlugin::create(QString const &key)
 {
+    if (key == QLatin1String(Q_MEDIASERVICE_MEDIAPLAYER))
+        return new QWinRTMediaPlayerService(this);
+
     return Q_NULLPTR;
 }
 
@@ -57,5 +63,8 @@ void QWinRTServicePlugin::release(QMediaService *service)
 QMediaServiceProviderHint::Features QWinRTServicePlugin::supportedFeatures(
         const QByteArray &service) const
 {
+    if (service == Q_MEDIASERVICE_MEDIAPLAYER)
+       return QMediaServiceProviderHint::StreamPlayback | QMediaServiceProviderHint::VideoSurface;
+
     return QMediaServiceProviderHint::Features();
 }