Restrict usage of mesa headers to targets that really need them

Restrict usage of mesa headers to targets that really need them

Many targets were getting mesa headers on their include paths even
though they never used them. This limits use of osmesa.h to the only
target that actually needs to interface directly with osmesa and
restricts use of the third_party/mesa/ headers to targets that need to
use the desktop GL bindings.

R=piman@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=290136

[jamesr, 2014-08-16 00:09:13]

ui/gl/gl_bindings.h needs the mesa headers to pick up <GL/gl.h>, but other than
that most things in chromium don't need the mesa headers at all.  This cuts down
a lot of unnecessary dependencies.

[piman, 2014-08-16 00:18:07]

lgtm

https://codereview.chromium.org/476403002/diff/1/ui/gl/DEPS
File ui/gl/DEPS (right):

https://codereview.chromium.org/476403002/diff/1/ui/gl/DEPS#newcode11
ui/gl/DEPS:11: # should use the headers from khronos.
That's kinda misleading... anything that uses gl_bindings.h does use mesa
headers.

[jamesr, 2014-08-16 00:21:05]

On 2014/08/16 00:18:07, piman (OOO) wrote:
> lgtm
> 
> https://codereview.chromium.org/476403002/diff/1/ui/gl/DEPS
> File ui/gl/DEPS (right):
> 
> https://codereview.chromium.org/476403002/diff/1/ui/gl/DEPS#newcode11
> ui/gl/DEPS:11: # should use the headers from khronos.
> That's kinda misleading... anything that uses gl_bindings.h does use mesa
> headers.

true. i could make the gl_bindings.h path full and expand this deps thing
(although gl_bindings.h will still need mesa on the include path).  do you think
that'd be clearer?  do we *ever* want gl_bindings.h to pick up the system
headers?

[piman, 2014-08-16 00:30:30]

On 2014/08/16 00:21:05, jamesr wrote:
> On 2014/08/16 00:18:07, piman (OOO) wrote:
> > lgtm
> > 
> > https://codereview.chromium.org/476403002/diff/1/ui/gl/DEPS
> > File ui/gl/DEPS (right):
> > 
> > https://codereview.chromium.org/476403002/diff/1/ui/gl/DEPS#newcode11
> > ui/gl/DEPS:11: # should use the headers from khronos.
> > That's kinda misleading... anything that uses gl_bindings.h does use mesa
> > headers.
> 
> true. i could make the gl_bindings.h path full and expand this deps thing
> (although gl_bindings.h will still need mesa on the include path).  do you
think
> that'd be clearer?  do we *ever* want gl_bindings.h to pick up the system
> headers?

Given that we generate gl_bindings.h from the mesa headers, I think the most
consistent thing is to use those. So no on the system headers.

I would just update the comment.

[jamesr, 2014-08-16 01:16:39]

The CQ bit was checked by jamesr@chromium.org

[jamesr, 2014-08-16 01:17:11]

On 2014/08/16 00:30:30, piman (OOO) wrote:
> Given that we generate gl_bindings.h from the mesa headers, I think the most
> consistent thing is to use those. So no on the system headers.
> 
> I would just update the comment.

I updated the DEPS rule to apply to osmesa.h specifically and added text to the
comment about using gl_bindings.h for access to desktop GL.

[commit-bot: I haz the power, 2014-08-16 01:19:19]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jamesr@chromium.org/476403002/20001

[piman, 2014-08-16 01:21:50]

Awesome, thanks, LGTM.

[commit-bot: I haz the power, 2014-08-16 08:29:55]

Committed patchset #2 (20001) as 290136