Webkit fails to render propertly as a ShaderEffectSource

 
import QtQuick 2.2
import QtWebKit 3.0

Rectangle {
    width: 2000
    height: 500

    WebView{
        id: web
        url: "http://maps.google.com"
        anchors.fill: parent
    }

    Loader{
        id: loader
    }
    ShaderEffectSource{
        id: fxSource
        sourceItem: web
        //hideSource: true
        textureSize: Qt.size(512,512)
    }
    ShaderEffect {
        id: shader
        width: 500; height: 500
        property variant src: fxSource
        //visible: false  // <-----ENABLE/DISABLE THIS
        vertexShader: "
                    uniform highp mat4 qt_Matrix;
                    attribute highp vec4 qt_Vertex;
                    attribute highp vec2 qt_MultiTexCoord0;
                    varying highp vec2 coord;
                    void main() {
                        coord = qt_MultiTexCoord0;
                        gl_Position = qt_Matrix * qt_Vertex;
                    }"
        fragmentShader: "
                    varying highp vec2 coord;
                    uniform sampler2D src;
                    uniform lowp float qt_Opacity;
                    void main() {
                        lowp vec4 tex = texture2D(src, coord);
                        gl_FragColor = tex;
                    }"
        MouseArea{
            drag.target: shader
            drag.axis: Drag.XandYAxis
        }
    }
}