Are all channels PGO now? I believe there's already a bug to get rid of the old win builders when that happens.

+waffles@ to make sure that we're really shipping PGO to all the Win & Win64 channels.

They should be, we're shipping the PGO builds to all the channels in M54+ (if we don't then we should). 

We need to keep the win builders as long as we support M53.

See crbug.com/640409 and crbug.com/625234 : We're shipping PGO to the Canary channels for x86 and x64.

FYI, Issue 629603 is the bug about getting rid of the old builders.

This is the right thing to do, but please hold off until after M54 has been promoted to Stable.  We still need to produce non-PGO x86 builds for M53.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6c0a80ee66d17702b05f21553c4d4e974b89d471

commit 6c0a80ee66d17702b05f21553c4d4e974b89d471
Author: sebmarchand <sebmarchand@chromium.org>
Date: Wed Sep 28 19:05:29 2016

Add a chrome_official_syzyasan_builder target.

This will ease the removal of the Syzygy optimization targets.

BUG= 651078 

Review-Url: https://codereview.chromium.org/2379683002
Cr-Commit-Position: refs/heads/master@{#421595}

[modify] https://crrev.com/6c0a80ee66d17702b05f21553c4d4e974b89d471/BUILD.gn

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/chrome/tools/build/+/e49a130068701472d5a8922c05c4722a555b146d

commit e49a130068701472d5a8922c05c4722a555b146d
Author: sebmarchand <sebmarchand@google.com>
Date: Wed Sep 28 19:09:34 2016

We're now shipping M54, time to remove the Syzygy stuffs?

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/chrome/tools/build/+/96975ce23297e519e6e8de1c83800ded27ec3546

commit 96975ce23297e519e6e8de1c83800ded27ec3546
Author: sebmarchand <sebmarchand@google.com>
Date: Mon Oct 17 14:10:06 2016

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/chrome/tools/build/+/c7c50660165325c7b6c1a85c1326fc4309d02c6a

commit c7c50660165325c7b6c1a85c1326fc4309d02c6a
Author: sebmarchand <sebmarchand@google.com>
Date: Mon Oct 17 16:52:26 2016

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/dc24dfdf83e70db531ca2dcb1d9a304415951400

commit dc24dfdf83e70db531ca2dcb1d9a304415951400
Author: sebmarchand <sebmarchand@chromium.org>
Date: Mon Oct 17 21:01:35 2016

Remove the syzygy optimization code.

BUG= 651078 

Review-Url: https://codereview.chromium.org/2420943002
Cr-Commit-Position: refs/heads/master@{#425775}

[modify] https://crrev.com/dc24dfdf83e70db531ca2dcb1d9a304415951400/BUILD.gn
[modify] https://crrev.com/dc24dfdf83e70db531ca2dcb1d9a304415951400/build/config/compiler/compiler.gni
[modify] https://crrev.com/dc24dfdf83e70db531ca2dcb1d9a304415951400/build/win/syzygy/syzygy.gni
[modify] https://crrev.com/dc24dfdf83e70db531ca2dcb1d9a304415951400/chrome/installer/mini_installer/BUILD.gn
[modify] https://crrev.com/dc24dfdf83e70db531ca2dcb1d9a304415951400/chrome/tools/build/win/FILES.cfg
[modify] https://crrev.com/dc24dfdf83e70db531ca2dcb1d9a304415951400/chrome/tools/build/win/syzygy/BUILD.gn

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/chrome/tools/build/+/4fc643596a74ba581971b4e755059118e6d57a43

commit 4fc643596a74ba581971b4e755059118e6d57a43
Author: sebmarchand <sebmarchand@google.com>
Date: Mon Oct 17 21:07:20 2016

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2a2c4b4e25392ba0e58be46cfa736b14623c1127

commit 2a2c4b4e25392ba0e58be46cfa736b14623c1127
Author: Sebastien Marchand <sebmarchand@chromium.org>
Date: Thu Oct 20 14:23:33 2016

Remove the syzygy optimization code.

BUG= 651078 , 656703

Review-Url: https://codereview.chromium.org/2420943002
Cr-Commit-Position: refs/heads/master@{#425775}
(cherry picked from commit dc24dfdf83e70db531ca2dcb1d9a304415951400)

Review URL: https://codereview.chromium.org/2439743002 .

Cr-Commit-Position: refs/branch-heads/2883@{#209}
Cr-Branched-From: 614d31daee2f61b0180df403a8ad43f20b9f6dd7-refs/heads/master@{#423768}

[modify] https://crrev.com/2a2c4b4e25392ba0e58be46cfa736b14623c1127/BUILD.gn
[modify] https://crrev.com/2a2c4b4e25392ba0e58be46cfa736b14623c1127/build/config/compiler/compiler.gni
[modify] https://crrev.com/2a2c4b4e25392ba0e58be46cfa736b14623c1127/build/win/syzygy/syzygy.gni
[modify] https://crrev.com/2a2c4b4e25392ba0e58be46cfa736b14623c1127/chrome/installer/mini_installer/BUILD.gn
[modify] https://crrev.com/2a2c4b4e25392ba0e58be46cfa736b14623c1127/chrome/tools/build/win/FILES.cfg
[modify] https://crrev.com/2a2c4b4e25392ba0e58be46cfa736b14623c1127/chrome/tools/build/win/syzygy/BUILD.gn

[Automated comment] removing mislabelled merge-merged-2840