Revert of Update V8 to version 4.2.1 (based on cf09a5a1912e0b1ba3dd92e4e67358618736f6aa).

Revert of Update V8 to version 4.2.1 (based on cf09a5a1912e0b1ba3dd92e4e67358618736f6aa). (patchset #1 id:1 of https://codereview.chromium.org/847343002/)

Reason for revert:
Speculative revert due to build failure on Win8 GN debug builder http://build.chromium.org/p/chromium.win/builders/Win8%20GN%20%28dbg%29/builds/2984

Original issue's description:
> Update V8 to version 4.2.1 (based on cf09a5a1912e0b1ba3dd92e4e67358618736f6aa).
>
> TBR=machenbach@chromium.org
>
> Committed: https://crrev.com/63aed1cdc517914528cbbe744b1ae89ba8dbdee6
> Cr-Commit-Position: refs/heads/master@{#311438}

TBR=machenbach@chromium.org,v8-autoroll@chromium.org
NOTREECHECKS=true
NOTRY=true

Committed: https://crrev.com/b75df192c6ba5394fb4d8edf5a66747e7da51b4f
Cr-Commit-Position: refs/heads/master@{#311445}

[Fabrice (no longer in Chrome), 2015-01-14 10:23:08]

Created Revert of Update V8 to version 4.2.1 (based on
cf09a5a1912e0b1ba3dd92e4e67358618736f6aa).

[commit-bot: I haz the power, 2015-01-14 10:24:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/852753002/1

[commit-bot: I haz the power, 2015-01-14 10:24:10]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-01-14 10:24:11]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[pasko-google - do not use, 2015-01-14 10:26:50]

lgtm, thank you

[Fabrice (no longer in Chrome), 2015-01-14 10:27:03]

The CQ bit was checked by fdegans@chromium.org

[commit-bot: I haz the power, 2015-01-14 10:27:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/852753002/1

[commit-bot: I haz the power, 2015-01-14 10:28:11]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-14 10:29:08]

Patchset 1 (id:??) landed as
https://crrev.com/b75df192c6ba5394fb4d8edf5a66747e7da51b4f
Cr-Commit-Position: refs/heads/master@{#311445}

[Michael Achenbach, 2015-01-14 10:36:43]

Meh - so why is there no trybot/cq coverage for this??