Android WebView不会询问地理位置权限

Question

我有一个android webview，当它加载使用地理定位的页面时，它不会询问权限。 webview没有显示任何内容。没有警报，没有！有什么问题？ 代码如下：

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);

        myWebView = (WebView)findViewById(R.id.webView);

        WebSettings webSettings = myWebView.getSettings();


        webSettings.setJavaScriptCanOpenWindowsAutomatically(true);

        myWebView.setWebViewClient(new WebViewClient());
        myWebView.setVerticalScrollBarEnabled(false);

        webSettings.setJavaScriptEnabled(true);
        webSettings.setGeolocationEnabled(true);

        myWebView.setWebChromeClient(new WebChromeClient() {

            public void onGeolocationPermissionsShowPrompt(String origin, GeolocationPermissions.Callback callback) {
                callback.invoke(origin, true, false);
            }

        });

        webSettings.setAppCacheEnabled(true);
        webSettings.setDatabaseEnabled(true);
        webSettings.setDomStorageEnabled(true);

        myWebView.loadUrl(URL);

    }

清单：

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_GPS" />
<uses-permission android:name="android.permission.ACCESS_ASSISTED_GPS" />
<uses-permission android:name="android.permission.ACCESS_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />