element.onresize

I'm not sure if this is the correct place for this but:

Has there been any discussion of adding an element.onresize event?

The issue that has come up is the canvas tag, in 2d or 3d, when the canvas
changes its displayed size, a webapp might want to respond by changing
the size of the internal representation of the canvas.

Unfortunately an appt has no way to know when the
canvas's display size has changed.

The developer can use window.onresize but that only triggers when the window
itself has changed size. If the canvas element has changed size for some
other
reason (another element's css or size were changed for example) no
window.onresize
is sent and so their is no easy way to know the display size of the canvas
changed.

This could be added to just the canvas tag but it seems like it would be
more
appropriate to be added to all (visual?) elements.

I can see for example, setting img.src depending on the display size of the
img element or changing the content of a div depending on its display size.