Update V8 to version 6.7.288.1

TBR=hablich@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;luci.chromium.try:android_optional_gpu_tests_rel

Change-Id: Ia59425425955af5593c37b3c35cdfe101f4ba938
Reviewed-on: https://chromium-review.googlesource.com/1009945
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550165}

DEPS

@@ -86,7 +86,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.
-  'v8_revision': '1231663280a834ae37f7240e377524828cb3efa3',
+  'v8_revision': '8457e810efd34381448d51d93f50079cf1f6a812',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling swarming_client
   # and whatever else without interference from each other.