Phóng to chử webview

private WebView mWebView;

// init web view and stuff like that ...


private void textSmaller() {

    WebSettings settings = mWebView.getSettings();
    settings.setTextZoom(settings.getTextZoom() - 10);
}

private void textBigger() {

    WebSettings settings = mWebView.getSettings();
    settings.setTextZoom(settings.getTextZoom() + 10);
}