webview正常加载iframe标签下的视频

mWebview = (WebView) inflate.findViewById(R.id.wb);
WebSettings webSettings = mWebview.getSettings();
// 设置WebView属性，能够执行Javascript脚本
webSettings.setJavaScriptEnabled(true);
webSettings.setPluginState(WebSettings.PluginState.ON);// 可以使用插件
webSettings.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.NARROW_COLUMNS);
mWebview.loadDataWithBaseURL(null,mExt.getTutorial(), "text/html",  "utf-8", null);