demos/declarative/webbrowser/webbrowser.qml fails

in a clone of the 4.7 branch on Wed March 10, 10:30

/usr/local/Trolltech/Qt-4.7.0 +% ./bin/qml demos/declarative/webbrowser/webbrowser.qml
QGtkStyle was unable to detect the current GTK+ theme.
file:///usr/local/Trolltech/Qt-4.7.0/demos/declarative/webbrowser/webbrowser.qml:47:9: Type FlickableWebView unavailable
FlickableWebView {
^
file:///usr/local/Trolltech/Qt-4.7.0/demos/declarative/webbrowser/content/FlickableWebView.qml:23:5: Type WebView unavailable
WebView {
^
Wall startup time: 21
^C