Remove memory corruption testing from base::File().

Remove memory corruption testing from base::File().

This was intended to help debug issue 424562 (see Issue 702473009 for
more details), and it isn't needed any more.

R=thakis@chromium.org,pasko@chromium.org,thestig@chromium.org
BUG=424562
Committed: https://crrev.com/ac9c196f4e34e0e11a220484bd3192635e619617
Cr-Commit-Position: refs/heads/master@{#351194}

[gavinp, 2015-09-28 16:01:28]

gavinp@chromium.org changed reviewers:
+ thestig@chromium.org

[gavinp, 2015-09-28 16:02:37]

thestig,pasko: PTAL.

This should have been done a while ago, but better late than never.

thestig: You're on the CL because Nico's set an away notice for October 9th,
otherwise I'd have asked him to review, as the reviewer of the original CL.

[pasko, 2015-09-28 16:09:51]

lgtm

[Lei Zhang, 2015-09-28 18:55:18]

lgtm

[Lei Zhang, 2015-09-28 18:55:22]

The CQ bit was checked by thestig@chromium.org

[commit-bot: I haz the power, 2015-09-28 18:57:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1372113002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1372113002/20001

[commit-bot: I haz the power, 2015-09-28 20:38:28]

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

[commit-bot: I haz the power, 2015-09-28 20:38:29]

Try jobs failed on following builders:
  linux_android_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_android_r...)

[gavinp, 2015-09-28 21:37:42]

The CQ bit was checked by gavinp@chromium.org

[commit-bot: I haz the power, 2015-09-28 21:38:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1372113002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1372113002/20001

[commit-bot: I haz the power, 2015-09-28 22:58:19]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-28 22:59:24]

Patchset 2 (id:??) landed as
https://crrev.com/ac9c196f4e34e0e11a220484bd3192635e619617
Cr-Commit-Position: refs/heads/master@{#351194}