For apps targeting the L release, WebView has a new default behavior that reduces memory footprint and increases performance by intelligently choosing the portion of the HTML document that needs to be drawn. These optimizations are transparent to the developers. However, under certain circumstances, an App developer may want to disable them: 1. When an app uses WebView.onDraw(android.graphics.Canvas) to do own drawing and accesses portions of the page that is way outside the visible portion of the page. 2. When an app uses WebView.CapturePicture to capture a very large HTML document. Note that capturePicture is a deprecated API. Enabling drawing the entire HTML document has a significant performance cost. This method should be called before any WebViews are created.