1. DomName('WebGLRenderingContext.getSupportedExtensions')
  2. DocsEditable()
List<String> getSupportedExtensions()

Source 

@DomName('WebGLRenderingContext.getSupportedExtensions')
@DocsEditable()
List<String> getSupportedExtensions() => _blink.BlinkWebGLRenderingContext.instance.getSupportedExtensions_Callback_0_(this);