Update V8 to version 3.29.64 (based on bleeding_edge revision r23926).

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/572583002

Cr-Commit-Position: refs/heads/master@{#294789}

DEPS

@@ -40,7 +40,7 @@ vars = {
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.
   'v8_branch': 'trunk',
-  'v8_revision': '6313e220249748eb26e1ddcee2bbe857fef03b42', # from svn revision 23887
+  'v8_revision': 'b376fed08cb9d90a3f67f655adf63c4b35feb106', # from svn revision 23929
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling WebRTC
   # and V8 without interference from each other.