Unresponsive script error on Domain Item highlighting.

[bmcdougald]

Getting unresponsive script messages when toggling to show domain items. This happened on multiple pages including this one: https://en.wikipedia.org/wiki/John_Kasich

This was discovered while testing duplicate value domain export fixes. Mike decided to track this ticket separately since there was no highlighting code changes in the branch under testing. His belief is this may be due to a threshold of extracted entities being hit.