useWideViewPort property
Set to true if the WebView should enable support for the "viewport" HTML meta tag or should use a wide viewport.
When the value of the setting is false, the layout width is always set to the width of the WebView control in device-independent (CSS) pixels.
When the value is true and the page contains the viewport meta tag, the value of the width specified in the tag is used.
If the page does not contain the tag or does not provide a width, then a wide viewport will be used. The default value is true.
Implementation
bool useWideViewPort;