Our Text element requests a texture size of 0 by 0 for empty strings.  This makes the texture allocation and drawing code very unhappy.

Check failed: surface_.get()

This happens when an element uses the kSingleLine (fixed height) configuration.  In this case, the text element sizes its width to fix its text.  In the kSingleLineFixedWidth case, the texture always ends up as the fixed width (even if there's no text).

This could cause a text binding to blow up an element.