Disable kEnableGpuMemoryBufferCompositorResources on Mac

Disable kEnableGpuMemoryBufferCompositorResources on Mac

This caused an uptick in crashes due to GpuMemoryBuffers failing to
allocate.

BUG=554541
TBR=reveman

Committed: https://crrev.com/c5b6a85810bd669a3916587ac4d70ac566351258
Cr-Commit-Position: refs/heads/master@{#359396}

[ccameron, 2015-11-12 20:18:44]

Description was changed from

==========
Disable kEnableGpuMemoryBufferCompositorResources on Mac

This caused an uptick in crashes due to GpuMemoryBuffers failing to
allocate.

BUG=554541
==========

to

==========
Disable kEnableGpuMemoryBufferCompositorResources on Mac

This caused an uptick in crashes due to GpuMemoryBuffers failing to
allocate.

BUG=554541
TBR=reveman
==========

[ccameron, 2015-11-12 20:18:46]

The CQ bit was checked by ccameron@chromium.org

[commit-bot: I haz the power, 2015-11-12 20:20:22]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1435133003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1435133003/1

[commit-bot: I haz the power, 2015-11-12 21:41:51]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-12 21:43:12]

Patchset 1 (id:??) landed as
https://crrev.com/c5b6a85810bd669a3916587ac4d70ac566351258
Cr-Commit-Position: refs/heads/master@{#359396}

[ccameron, 2015-11-24 03:38:39]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1470213002/ by ccameron@chromium.org.

The reason for reverting is: This is no longer needed now that 48 has branched
and https://codereview.chromium.org/1463853002/ is landed..