Add allocator shim test to ffmpeg test suite.

Add allocator shim test to ffmpeg test suite.

This just verifies that the allocator shim is correctly installed on Windows, the rest of the allocator shim tests are in base_unittests and allocator_unittests.

This depends on https://codereview.chromium.org/868533003/ and https://gerrit.chromium.org/gerrit/#/c/73563

BUG=450676
TEST=media_unittests

Committed: https://crrev.com/8ec02a10ee3d563034b5a53552b612ad7f15d834
Cr-Commit-Position: refs/heads/master@{#312841}

[Will Harris, 2015-01-22 04:42:43]

wfh@chromium.org changed reviewers:
+ dalecurtis@chromium.org

[DaleCurtis, 2015-01-22 18:37:37]

lgtm

[Will Harris, 2015-01-23 06:57:38]

The CQ bit was checked by wfh@chromium.org

[commit-bot: I haz the power, 2015-01-23 06:58:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/865113002/1

[commit-bot: I haz the power, 2015-01-23 07:13:26]

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

[commit-bot: I haz the power, 2015-01-23 07:13:27]

Try jobs failed on following builders:
  linux_chromium_rel_ng on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Will Harris, 2015-01-23 08:11:58]

The CQ bit was checked by wfh@chromium.org

[commit-bot: I haz the power, 2015-01-23 08:13:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/865113002/1

[commit-bot: I haz the power, 2015-01-23 08:13:32]

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

[commit-bot: I haz the power, 2015-01-23 08:13:33]

Try jobs failed on following builders:
  linux_chromium_rel_ng on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Will Harris, 2015-01-23 14:34:46]

The CQ bit was checked by wfh@chromium.org

[commit-bot: I haz the power, 2015-01-23 14:36:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/865113002/1

[commit-bot: I haz the power, 2015-01-23 14:37:40]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-23 14:38:25]

Patchset 1 (id:??) landed as
https://crrev.com/8ec02a10ee3d563034b5a53552b612ad7f15d834
Cr-Commit-Position: refs/heads/master@{#312841}