A mixin which adds the PerformanceWatchdog widget to the Viewer widget. Rather than being called directly, this function is normally passed as a parameter to Viewer#extend, as shown in the example below.
Name Type Default Description
viewer Viewer The viewer instance.
options.lowFrameRateMessage String 'This application appears to be performing poorly on your system. Please try using a different web browser or updating your video drivers.' optional The message to display when a low frame rate is detected. The message is interpeted as HTML, so make sure it comes from a trusted source so that your application is not vulnerable to cross-site scripting attacks.
var viewer = new Cesium.Viewer('cesiumContainer');
viewer.extend(Cesium.viewerPerformanceWatchdogMixin, {
    lowFrameRateMessage : 'Why is this going so <em>slowly</em>?'