GitLab

Original cl
https://codereview.chromium.org/1035983003/

In order for ChromeVox to queue up utterances, we can separate each attribute or rule into its own spannable. Each spannable is then sent to tts (queueing as needed).

BUG=477492
TBR=dtseng@chromium.org

Review URL: https://codereview.chromium.org/1094463003

Cr-Commit-Position: refs/heads/master@{#325542}