Revert of Add d8 API for spawning function on a new thread (Second try)

Revert of Add d8 API for spawning function on a new thread (Second try) (patchset #3 id:60001 of https://codereview.chromium.org/1195613003/)

Reason for revert:
Fails on V8 Linux - isolates (http://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20isolates/builds/4128)

Original issue's description:
> Add d8 API for spawning function on a new thread (Second try)
>
> This API closely matches the Worker API. The differences:
>
> 1) The argument to the Worker constructor is a function to run, not a script.
> 2) Receiving a message from a worker is a synchronous API (as there is no event
> loop).
>
> The serialization done here is not robust as the real DOM implementation. For
> example, recursive data structures or otherwise duplicated objects are not
> allowed.
>
> BUG=chromium:497295
> R=jochen@chromium.org
> LOG=n
>
> Review URL: https://codereview.chromium.org/1185643004
>
> Cr-Commit-Position: refs/heads/master@{#29126}
>
> Committed: https://crrev.com/ec2eaf712ecee6b4891c0458f2397e04a1f9b339
> Cr-Commit-Position: refs/heads/master@{#29158}

TBR=jochen@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:497295
Committed: https://crrev.com/4f8761ca4e9c5ac89e787caeabf4fb27814424fc
Cr-Commit-Position: refs/heads/master@{#29161}

[binji, 2015-06-19 18:31:44]

Created Revert of Add d8 API for spawning function on a new thread (Second try)

[commit-bot: I haz the power, 2015-06-19 18:32:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1191373005/1

[commit-bot: I haz the power, 2015-06-19 18:32:08]

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

[commit-bot: I haz the power, 2015-06-19 18:32:10]

No L-G-T-M from a valid reviewer yet. Only full committers are accepted.
Even if an L-G-T-M 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.

[adamk, 2015-06-19 18:33:22]

adamk@chromium.org changed reviewers:
+ adamk@chromium.org

[adamk, 2015-06-19 18:33:22]

The CQ bit was checked by adamk@chromium.org

[adamk, 2015-06-19 18:33:23]

lgtm

[commit-bot: I haz the power, 2015-06-19 18:33:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1191373005/1

[commit-bot: I haz the power, 2015-06-19 18:34:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-19 18:34:14]

Patchset 1 (id:??) landed as
https://crrev.com/4f8761ca4e9c5ac89e787caeabf4fb27814424fc
Cr-Commit-Position: refs/heads/master@{#29161}