Make the Sk GL context class an abstract base class

Make the Sk GL context class an abstract base class

Make the Sk GL context class, SkGLNativeContext, an abstract base class. Before,
it depended on ifdefs to implement the platform dependent polymorphism.  Move
the logic to subclasses of the various platform implementations.

This a step to enable Skia embedders to compile dm and bench_pictures. The
concrete goal is to support running these test apps with Chromium command buffer.

With this change, Chromium can implement its own version of SkGLNativeContext
that uses command buffer, and host the implementation in its own repository.

Implements the above by renaming the SkGLContextHelper to SkGLContext and
removing the unneeded SkGLNativeContext. Also removes
SkGLNativeContext::AutoRestoreContext functionality, it appeared to be unused:
no use in Skia code, and no tests.

BUG=skia:2992
Committed: https://skia.googlesource.com/skia/+/a90ed4e83897b45d6331ee4c54e1edd4054de9a8

Committed: https://skia.googlesource.com/skia/+/9e61bb7815b133bc40ea7b00fccc853f4b728e3c

[Kimmo Kinnunen, 2014-10-06 11:59:23]

kkinnunen@nvidia.com changed reviewers:
+ bsalomon@google.com

[Kimmo Kinnunen, 2014-10-06 11:59:24]

Would this be acceptable, if I fix the compile problems for win + mac, hope IOS
works, and let you pick the names?

Wrt the names: either the _unix etc files need to be renamed, or the new
abstract base class needs to be renamed.

[bsalomon, 2014-10-06 12:56:37]

I like it.  I'm especially excited about running the Skia test apps against the
command buffer.

A few minor things:

We don't usually Sk-prefix names of classes defined in .cpp files (e.g. it could
just be GLContext or IOSGLContext, etc).

We recently renamed the GrGLInterface that uses glx from "unix" to "glx". We
should do the same here.

Since we don't have a class called SkNativeGLContext anymore we can drop
"Native" from the files SkNativeGLContext_<platform>.cpp

Can we call the  factory function SkCreatePlatformGLContext?

https://codereview.chromium.org/630843002/diff/1/include/gpu/GrContextFactory.h
File include/gpu/GrContextFactory.h (right):

https://codereview.chromium.org/630843002/diff/1/include/gpu/GrContextFactory...
include/gpu/GrContextFactory.h:210: SkGLContext*        fGLContext;
can you realign these?

[Kimmo Kinnunen, 2014-10-07 14:01:30]

On 2014/10/06 12:56:37, bsalomon wrote:
> We don't usually Sk-prefix names of classes defined in .cpp files (e.g. it
could
> just be GLContext or IOSGLContext, etc).
Done.

> We recently renamed the GrGLInterface that uses glx from "unix" to "glx". We
> should do the same here.
Done.

> Since we don't have a class called SkNativeGLContext anymore we can drop
> "Native" from the files SkNativeGLContext_<platform>.cpp
Done.


> Can we call the  factory function SkCreatePlatformGLContext?
Done.
 
>
https://codereview.chromium.org/630843002/diff/1/include/gpu/GrContextFactory.h
> File include/gpu/GrContextFactory.h (right):
> 
>
https://codereview.chromium.org/630843002/diff/1/include/gpu/GrContextFactory...
> include/gpu/GrContextFactory.h:210: SkGLContext*        fGLContext;
> can you realign these?
Done.


I've checked linux and windows+angle builds. mac, ios builds have not been
checked. nacl seems to compile, but probably the compilation did not try the gpu
parts..

[bsalomon, 2014-10-08 10:55:16]

lgtm

[Kimmo Kinnunen, 2014-10-08 11:05:49]

The CQ bit was checked by kkinnunen@nvidia.com

[commit-bot: I haz the power, 2014-10-08 11:06:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/630843002/60001

[commit-bot: I haz the power, 2014-10-08 11:14:29]

Committed patchset #4 (id:60001) as a90ed4e83897b45d6331ee4c54e1edd4054de9a8

[bsalomon, 2014-10-08 11:43:54]

A revert of this CL (patchset #4 id:60001) has been created in
https://codereview.chromium.org/639793002/ by bsalomon@google.com.

The reason for reverting is: nanobech failing on Android.

[Kimmo Kinnunen, 2014-10-08 12:32:47]

On 2014/10/08 11:43:54, bsalomon wrote:
> The reason for reverting is: nanobech failing on Android.

Ah, sorry. Updated the patches and verified that nanobench runs on android.

Brian, would it be possible for you to trigger the iOS trybot? I tried to fix
the problem, but I don't have an IOS build env available just yet.

[bsalomon, 2014-10-08 12:38:10]

On 2014/10/08 12:32:47, Kimmo Kinnunen wrote:
> On 2014/10/08 11:43:54, bsalomon wrote:
> > The reason for reverting is: nanobech failing on Android.
> 
> Ah, sorry. Updated the patches and verified that nanobench runs on android.
> 
> Brian, would it be possible for you to trigger the iOS trybot? I tried to fix
> the problem, but I don't have an IOS build env available just yet.

Sure, just triggered them.

[Kimmo Kinnunen, 2014-10-09 12:15:29]

The CQ bit was checked by kkinnunen@nvidia.com

[commit-bot: I haz the power, 2014-10-09 12:16:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/630843002/80001

[commit-bot: I haz the power, 2014-10-09 12:24:20]

Committed patchset #5 (id:80001) as 9e61bb7815b133bc40ea7b00fccc853f4b728e3c