Update V8 to version 4.5.45.

Summary of changes available at:
https://chromium.googlesource.com/v8/v8/+log/be35c6f9..9efbfe82

Please follow these instructions for assigning/CC'ing issues:
https://code.google.com/p/v8-wiki/wiki/TriagingIssues

TBR=hablich@chromium.org,machenbach@chromium.org,yangguo@chromium.org,vogelheim@chromium.org

Review URL: https://codereview.chromium.org/1169853010

Cr-Commit-Position: refs/heads/master@{#333595}

DEPS

@@ -38,7 +38,7 @@ 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': 'be35c6f967fffdaccc9f176527bcc1f00a8f61ab',
+  'v8_revision': '9efbfe82369fb488e27dc77040d3b7efeaafbdf2',
   # 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.