experimental/editor: Find nearest possible cursor position when click in whitespace

Bug: skia:9020
Change-Id: Ieb1f7a545ab3458db7124535b3be3c3d589bf1be
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/229388
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
1 file changed