Delete obsolete XPointer range-to function.

BUG=623378

Review-Url: https://codereview.chromium.org/2127493002
Cr-Commit-Position: refs/heads/master@{#403859}
(cherry picked from commit b6ad54b72c7f8c422c288dd9c8756d2a15f30e53)

Review URL: https://codereview.chromium.org/2154263005 .

Cr-Commit-Position: refs/branch-heads/2785@{#206}
Cr-Branched-From: 68623971be0cfc492a2cb0427d7f478e7b214c24-refs/heads/master@{#403382}
3 files changed