Update V8 to version 4.2.42 (based on 52d4d7de2e2c0874dad7a02943481ea374bc3958).

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/891963002

Cr-Commit-Position: refs/heads/master@{#314079}

DEPS

@@ -47,7 +47,7 @@ vars = {
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.
   'v8_branch': 'trunk',
-  'v8_revision': '07d05ef027287d6401902d9bc8ea1e7bb9d13b90',
+  'v8_revision': 'f349f6abc31eb2440033c7ec74dc434c885cd793',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling WebRTC
   # and V8 without interference from each other.