destroy webbiew avoid memory leak

webview destroy

public void destroyAll() {
        for (WebView webview : mWebViews) {
            if (webview != null) {
                webview.onPause();
                webview.stopLoading();
                webview.setWebViewClient(null);
                webview.removeAllViews();
                webview.clearHistory();
                webview.clearCache(true);
                webview.destroy();
                ViewParent parent = webview.getParent();
                if (parent != null && parent instanceof ViewGroup) {
                    ViewGroup oldParent = (ViewGroup) parent;
                    oldParent.removeView(webview);
                }
                webview = null;
            }
        }
    }