gpu: Fix dependency cycle between service_sources and config_sources.

gpu: Fix dependency cycle between service_sources and config_sources.

ERROR Dependency cycle:
  //gpu/command_buffer/service:service_sources ->
  //gpu/config:config_sources ->
  //gpu/command_buffer/service:service_sources

The problem was that gpu/command_buffer/service already include from
gpu/config, but gpu/config were also including from
gpu/command_buffer/service for gpu_switches.h, creating the above
dependency cycle.

By moving the required switch down to gpu/config, we broke this
dependency cycle.

With that 'gn check' passes for gpu/config with the following command
lines:

$ gn gen out-gn/Debug
$ gn check out-gn/Debug //gpu/config/*

gpu/command_buffer/service needs more work to pass 'gn check' though.

BUG=367595, 376000
TEST=see above
R=sievers@chromium.org

Committed: https://crrev.com/15525c4fa7633018873aa4fec407a14c5cf64840
Cr-Commit-Position: refs/heads/master@{#327344}

[no sievers, 2015-04-27 23:00:34]

sievers@chromium.org changed reviewers:
+ zmo@chromium.org

[no sievers, 2015-04-28 00:12:37]

lgtm if zmo@ is happy too

[Zhenyao Mo, 2015-04-28 00:18:18]

It's still failing a lot of bots.  Be happy to review it when the bots are
happy.

[tfarina, 2015-04-28 01:54:28]

Wait, I don't have
gpu/command_buffer/service/gles2_cmd_decoder_unittest_context_lost.cc in my
checkout. Is it coming from src-internal?

[tfarina, 2015-04-28 03:23:49]

Zhenyao, bots are all green now. PTAL.

[Zhenyao Mo, 2015-04-28 16:41:28]

LGTM with nits

https://codereview.chromium.org/1103403002/diff/120001/gpu/command_buffer/ser...
File gpu/command_buffer/service/gpu_switches.cc (right):

https://codereview.chromium.org/1103403002/diff/120001/gpu/command_buffer/ser...
gpu/command_buffer/service/gpu_switches.cc:8: #include
"gpu/config/gpu_switches.h"
nit: No need because you included it in .h file already

https://codereview.chromium.org/1103403002/diff/120001/gpu/command_buffer/ser...
File gpu/command_buffer/service/gpu_switches.h (right):

https://codereview.chromium.org/1103403002/diff/120001/gpu/command_buffer/ser...
gpu/command_buffer/service/gpu_switches.h:11: #include "gpu/gpu_export.h"
nit: you don't need gpu_export.h here, because gpu/config/gpu_switches.h already
included it.

[tfarina, 2015-04-28 18:07:23]

https://codereview.chromium.org/1103403002/diff/120001/gpu/command_buffer/ser...
File gpu/command_buffer/service/gpu_switches.cc (right):

https://codereview.chromium.org/1103403002/diff/120001/gpu/command_buffer/ser...
gpu/command_buffer/service/gpu_switches.cc:8: #include
"gpu/config/gpu_switches.h"
On 2015/04/28 16:41:28, Zhenyao Mo wrote:
> nit: No need because you included it in .h file already

Done.

https://codereview.chromium.org/1103403002/diff/120001/gpu/command_buffer/ser...
File gpu/command_buffer/service/gpu_switches.h (right):

https://codereview.chromium.org/1103403002/diff/120001/gpu/command_buffer/ser...
gpu/command_buffer/service/gpu_switches.h:11: #include "gpu/gpu_export.h"
On 2015/04/28 16:41:28, Zhenyao Mo wrote:
> nit: you don't need gpu_export.h here, because gpu/config/gpu_switches.h
already
> included it.

This is good for iwyu. I kept it.

[tfarina, 2015-04-28 18:07:29]

The CQ bit was checked by tfarina@chromium.org

[tfarina, 2015-04-28 18:07:30]

The patchset sent to the CQ was uploaded after l-g-t-m from
sievers@chromium.org, zmo@chromium.org
Link to the patchset: https://codereview.chromium.org/1103403002/#ps140001
(title: "zmo nits")

[commit-bot: I haz the power, 2015-04-28 18:08:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1103403002/140001

[commit-bot: I haz the power, 2015-04-28 19:04:33]

Committed patchset #8 (id:140001)

[commit-bot: I haz the power, 2015-04-28 19:05:22]

Patchset 8 (id:??) landed as
https://crrev.com/15525c4fa7633018873aa4fec407a14c5cf64840
Cr-Commit-Position: refs/heads/master@{#327344}