[skottie slide] Don't assume we have a text editor

We only instantiate a text editor when text layers are present, so we
need to guard against the null case.

Change-Id: If73f41deea4c5365f2610044a5147d2091f1422e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/629619
Reviewed-by: Jorge Betancourt <jmbetancourt@google.com>
Commit-Queue: Jorge Betancourt <jmbetancourt@google.com>
Auto-Submit: Florin Malita <fmalita@chromium.org>
1 file changed