GitLab

Modifies pepper_hash_for_uma to sort the output by hash, so it's
easier to compare against the histogram.xml file when searching
for missing hashes.

I used the following script to get an API list from src/ppapi:

grep -r "PPB_" ppapi/c | grep -o "\".*;[0-9]\.[0-9]*\"" | tr '\n' ' '

BUG=
R=asvitkine@chromium.org, dmichael@chromium.org

Review URL: https://codereview.chromium.org/938283004

Cr-Commit-Position: refs/heads/master@{#318170}