ss="description-from-type-label">Description copied from class:&nbsp;<code><a href="../sketch/Surface.html#onCopyOnWrite(int)">Surface</a></code></span></div>
<div class="block">If the surface is about to change, we call this so that our subclass
 can optionally fork their backend (copy-on-write) in case it was
 being shared with the cachedImage.
 <p>
 Returns false if the backing cannot be un-shared.</div>
<dl class="notes">
<dt>Specified by:</dt>
<dd><code><a href="../sketch/Surface.html#onCopyOnWrite(int