GitLab

- Mark some SpellcheckHunspellDictionary code non-Android.
- Use base::StringPiece a little more.
- Fix nits / style.

Change-Id: Ibe2e7bf14678f7fbfc976d42964091afa138bbec
Reviewed-on: https://chromium-review.googlesource.com/838370Reviewed-by: Rouslan Solomakhin <rouslan@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532198}