ss="member-name-link">onCopyOnWrite</a><wbr>(int&nbsp;changeMode)</code></div>
<div class="col-last odd-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4">
<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.</div>
</div>
<div class="col-first even-row-color method-summary-table method-summary-table-tab2 method-summary-table-tab4"><code>pro