1. In textFlow_compositionCompleteHandler(), handle rounding error if returned contentWidth/Height is just over requested width/height. This should never be the case but it is, so deal with it so an infinite loop between the TextView and the scroller can be avoided.
2. Make the in-focus cursor, black, with inverted blend mode, so it will have max. visibility against whatever background color is being used.
3. Check pointer before access in focusInHandler()/focusOutHandler() since it is null if the component is not editable and not selectable.
4. If halo text component inherits it's styles from a gumbo component it's possible that there are invalid style properties for halo. Handle the narrow case where textAlign is "start" or "end". There are probably other cases and we need to look for these.
QE Notes: for SDK-19106 also test cursor against black/dark background (contentBackgroundColor="black")
Bugs: SDK-19144/SDK-19155, SDK-19106, SDK-19025, SDK-19140