1. @DomName('WebGLRenderingContext.copyTexImage2D')
  2. @DocsEditable()
void copyTexImage2D(int target, int level, int internalformat, int x, int y, int width, int height, int border)

Source 

@DomName('WebGLRenderingContext.copyTexImage2D')
@DocsEditable()
void copyTexImage2D(int target, int level, int internalformat, int x, int y,
        int width, int height, int border) =>
    _blink.BlinkWebGLRenderingContext.instance.copyTexImage2D_Callback_8_(
        this, target, level, internalformat, x, y, width, height, border);