[TextBlob] Fall back to TightRunBounds when the font bounds are empty
Empty font bounds are likely an indication of a font bug. As a best
effort, we can use TightRunBounds in this easily detectable case.
Since TightRunBounds only supports kDefault_Positioning currently, the
CL also reinstates handling of kFull_Positioning and
kHorizontal_Positioning (removed in http://crrev.com/858153007).
BUG=507022
R=reed@google.com,bungeman@google.com
Review URL: https://codereview.chromium.org/1399123002
1 file changed