Rolling v8/testing/gtest to 23574bf2333f834ff665f894c97bef8a5b33a0a9

Rolling v8/tools/clang to 17e168207560f2dfdf95e50c5eb79e6d3ac1eaf6

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/1136913007

Cr-Commit-Position: refs/heads/master@{#28400}