Qt wayland surface is empty when gst-launch client is playing video

QWaylandShell surface is empty when the gst-launch streams video to it on the Elina Linux. All works OK with Weston.

Reproducing steps:

1. Compile the minimal-qml compositor, copy to the target and launch it by run-compositor.sh script
2. Copy a test video (1920x1080 h264) and the run-client-test.sh script to the same directory in the target
3. Start gst-launch streaming by the run-client-test.sh
4. Add in the minimal-qml GUI a new Wayland surface

Expected results: A surface is created and the video is displayed on the surface

Actual result: An empty surface is created

NOTE: If the Weston used as a compositor instead of the minimal-qml, the video is displayed successfully on the surface. The GStreamer version is 1.8.3.

gst_log_client.7z - debug log from connected to minimal-qml gst client
compositor_qt.txt - terminal log of minimal-qml compositor
client_qt.txt - terminal log from connected to minimal-qml gst client
gst_log_client_weston.7z - debug log from connected to Weston gst client
client_weston.txt - terminal log from connected to Weston gst client