Roll src/third_party/catapult/ fa6d5ce49..4a7b232d0 (2 commits).

https://chromium.googlesource.com/external/github.com/catapult-project/catapult.git/+log/fa6d5ce49e34..4a7b232d00cc

$ git log fa6d5ce49..4a7b232d0 --date=short --no-merges --format='%ad %ae %s'
2017-01-06 benjhayden Update UserModelBuilder to an ES6 class.
2017-01-06 benjhayden Modernize UserExpectationVerifier.

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, see:
http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium#TOC-Failures-due-to-DEPS-rolls

CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel
TBR=catapult-sheriff@chromium.org

Review-Url: https://codereview.chromium.org/2618943003
Cr-Commit-Position: refs/heads/master@{#442112}

DEPS

@@ -96,7 +96,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling catapult
   # and whatever else without interference from each other.
-  'catapult_revision': 'fa6d5ce49e34594c2914c6ac6db09836692ee5dd',
+  'catapult_revision': '4a7b232d00ccf95393c58640c139723542df573e',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling libFuzzer
   # and whatever else without interference from each other.