Record code coverage in canvaskit tests, increase coverage

Fix a bug with paragraph text direction that an incorrect unit test wasn't detecting.

Change-Id: I73418ea8a90da097078d93ddf8692a55488f672f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/292366
Commit-Queue: Nathaniel Nifong <nifong@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
11 files changed