Remove unused free function GetIOSChromeParseJSONCallback()

This function is never used except in the function unit tests.
Remove it and the corresponding unit tests.

Bug: 842655, 964232, 714018
Change-Id: Ia0e2f85dd86019db776dfed9980b4800def49580
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1627370
Auto-Submit: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662572}
8 files changed