id String - The identifier of a window or screen that can be used as a chromeMediaSourceId constraint when calling [navigator.webkitGetUserMedia]. The format of the identifier will be window:XX or screen:XX, where XX is a random generated number.name String - A screen source will be named either Entire Screen or Screen <index>, while the name of a window source will match the window title.thumbnail NativeImage - A thumbnail image. Note: There is no guarantee that the size of the thumbnail is the same as the thumbnailSize specified in the options passed to desktopCapturer.getSources. The actual size depends on the scale of the screen or window.