[SH iOS] Adding text fragment parsing

Before the text fragment can be sent to the JavaScript that will
highlight/scroll the page accordingly, it needs to be parsed into
components according to the spec.

Bug: 1099268
Change-Id: I75d281996b922542aea25501bc22f064a1a5ac73
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2337407
Reviewed-by: Gayane Petrosyan <gayane@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Commit-Queue: Tommy Martino <tmartino@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#795486}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 191a023aed0e504a3714018cf472896c28edc5f5
3 files changed