Access to GPS does not work in Android QtWebView

Here's minimal QML to test geolocation support by using google api example page:

import QtQuick 2.5
import QtQuick.Window 2.2
import QtWebView 1.1

Window {
    visible: true

    WebView {
        anchors.fill: parent
        url: 'https://developers.google.com/maps/documentation/javascript/examples/map-geolocation'
    }
}

AndroidManifext.xml contains:

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

Test app settings shows that there is available permission:
precise location (GPS and network based)

But when Google Maps API example page loads, popup appears with text:
Error: The Geolocation service failed.

openstreetmaps.org also shows error:
Geolocationerror: User denied Geolocation.

There is no user prompt asking about permission. When openstreetmaps.org is opened in Chrome browser (not webview), it works OK after prompt.

I cannot test with iOS though.