Simplify WeakMap and WeakSet tests slightly.

Simplify WeakMap and WeakSet tests slightly.

R=rossberg@chromium.org
TEST=cctest/test-weakmaps,cctest/test-weaksets

Committed: https://crrev.com/a90d7a871da19d33e93c8779186408c8d1615cac
Cr-Commit-Position: refs/heads/master@{#26428}

[rossberg, 2015-02-04 13:16:00]

lgtm

[yurys, 2015-02-04 13:16:23]

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

[yurys, 2015-02-04 13:16:24]

lgtm, I should have done it in my CL.

[Michael Starzinger, 2015-02-04 13:19:30]

The CQ bit was checked by mstarzinger@chromium.org

[commit-bot: I haz the power, 2015-02-04 13:20:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/903463002/1

[commit-bot: I haz the power, 2015-02-04 13:36:55]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-04 13:37:14]

Patchset 1 (id:??) landed as
https://crrev.com/a90d7a871da19d33e93c8779186408c8d1615cac
Cr-Commit-Position: refs/heads/master@{#26428}

[yurys, 2015-02-04 15:10:36]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/899833003/ by yurys@chromium.org.

The reason for reverting is: Revert this patch as the original CL has to be
reverted to due to shared win build failure

http://build.chromium.org/p/client.v8/builders/V8%20Win32%20-%20nosnap%20-%20....