Caused new failures on fast/text-autosizing/cluster-inline-grid-flex-box.html

Revert "constructTextRun doesn't require a call to bloatedCharacters()"

This reverts commit bc4eff3a148197d088f8ed9b394660bd0526401e.

git-svn-id: svn://svn.chromium.org/blink/trunk@154291 bbb929c8-8fbe-4397-9dbb-9b2b20218538