GitLab

Set-up response creation in JavaScript and handling in
CRWTextFragmentsHandler, allowing the collection of success/failure
metrics and measurement of the JavaScript library's rate of success.

Bug: 1136043
Change-Id: I01eea5d85e2827a496b011d116592bebb74bd92e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2448683
Commit-Queue: Sebastien Lalancette <seblalancette@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Reviewed-by: Tommy Martino <tmartino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814791}