Fix context creation problems in dm

Fix context creation problems in dm

Fixes these issues:

1. The glXCreateContextAttribsARB call seems to modify the
context_attrib parameter upon failure. Since context_attrib was static,
if it first tried to create an OpenGL 4.4 context and it failed, further
attempts to create a context with lower versions would also fail.

2. Getting an OpenGL 3.0 context was never tried.

3. Context creation for ES 3.0 was failing on my machine. Since ES 2.0
looks like the intended version from the surrounding code, I set it to
that. It could be rewritten to use a similar loop as standard OpenGL and
try from the highest version to the lowest.

BUG=skia:5403
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2147513002

Committed: https://skia.googlesource.com/skia/+/7b70156334629c083040f4d175e23b8743f53153

[mkollaro, 2016-07-12 14:03:10]

Description was changed from

==========
Fix context creation problems in dm

Fixes these issues:

1. The glXCreateContextAttribsARB call seems to modify the
context_attrib parameter upon failure. Since context_attrib was static,
if it first tried to create an OpenGL 4.4 context and it failed, further
attempts to create a context with lower versions would also fail.

2. Getting an OpenGL 3.0 context was never tried.

3. Context creation for ES 3.0 was failing on my machine. Since ES 2.0
looks like the intended version from the surrounding code, I set it to
that. It could be rewritten to use a similar loop as standard OpenGL and
try from the highest version to the lowest.

BUG=skia:5403
==========

to

==========
Fix context creation problems in dm

Fixes these issues:

1. The glXCreateContextAttribsARB call seems to modify the
context_attrib parameter upon failure. Since context_attrib was static,
if it first tried to create an OpenGL 4.4 context and it failed, further
attempts to create a context with lower versions would also fail.

2. Getting an OpenGL 3.0 context was never tried.

3. Context creation for ES 3.0 was failing on my machine. Since ES 2.0
looks like the intended version from the surrounding code, I set it to
that. It could be rewritten to use a similar loop as standard OpenGL and
try from the highest version to the lowest.

BUG=skia:5403
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2147513002
==========

[mkollaro, 2016-07-12 14:08:30]

martina.kollarova@intel.com changed reviewers:
+ bsalomon@google.com, reed@google.com

[mkollaro, 2016-07-12 14:08:31]

I'm thinking about rewriting it into a single loop that would try creating the
highest version standard OpenGL or ES context. The fallback 2.0 context creation
is probably just a leftover from copy-pasting [1] and could be merged into it.
What do you think?

[1] https://www.opengl.org/wiki/Tutorial:_OpenGL_3.0_Context_Creation_(GLX)

[mkollaro, 2016-07-12 14:10:19]

The CQ bit was checked by martina.kollarova@intel.com to run a CQ dry run

[commit-bot: I haz the power, 2016-07-12 14:10:20]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-12 14:14:50]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-07-12 14:14:51]

Dry run: Try jobs failed on following builders:
  Build-Win-MSVC-x86_64-Debug-Trybot on master.client.skia.compile (JOB_FAILED,
http://build.chromium.org/p/client.skia.compile/builders/Build-Win-MSVC-x86_6...)

[bsalomon, 2016-07-12 15:22:05]

On 2016/07/12 14:08:31, mkollaro wrote:
> I'm thinking about rewriting it into a single loop that would try creating the
> highest version standard OpenGL or ES context. The fallback 2.0 context
creation
> is probably just a leftover from copy-pasting [1] and could be merged into it.
> What do you think?
> 
> [1] https://www.opengl.org/wiki/Tutorial:_OpenGL_3.0_Context_Creation_(GLX)

Rewriting as one loops sounds like a good idea.. This lgtm, but could you add a
comment about glXCreateContextAttribsARB modifying the attribs? I'd just like to
capture that so we don't readd the same bug in the future.

[mkollaro, 2016-07-18 10:21:43]

The CQ bit was checked by martina.kollarova@intel.com to run a CQ dry run

[commit-bot: I haz the power, 2016-07-18 10:21:51]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-18 10:38:23]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-07-18 10:38:23]

Dry run: This issue passed the CQ dry run.

[mkollaro, 2016-07-20 08:32:26]

On 2016/07/12 15:22:05, bsalomon wrote:
> On 2016/07/12 14:08:31, mkollaro wrote:
> > I'm thinking about rewriting it into a single loop that would try creating
the
> > highest version standard OpenGL or ES context. The fallback 2.0 context
> creation
> > is probably just a leftover from copy-pasting [1] and could be merged into
it.
> > What do you think?
> > 
> > [1] https://www.opengl.org/wiki/Tutorial:_OpenGL_3.0_Context_Creation_(GLX)
> 
> Rewriting as one loops sounds like a good idea.. This lgtm, but could you add
a
> comment about glXCreateContextAttribsARB modifying the attribs? I'd just like
to
> capture that so we don't readd the same bug in the future.

Done. I'll try the single-loop rewrite in another commit.

[bsalomon, 2016-07-20 13:47:41]

The CQ bit was checked by bsalomon@google.com

[bsalomon, 2016-07-20 13:47:41]

The patchset sent to the CQ was uploaded after l-g-t-m from bsalomon@google.com
Link to the patchset: https://codereview.chromium.org/2147513002/#ps40001
(title: "add comment about static")

[commit-bot: I haz the power, 2016-07-20 13:47:53]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-20 14:01:48]

Description was changed from

==========
Fix context creation problems in dm

Fixes these issues:

1. The glXCreateContextAttribsARB call seems to modify the
context_attrib parameter upon failure. Since context_attrib was static,
if it first tried to create an OpenGL 4.4 context and it failed, further
attempts to create a context with lower versions would also fail.

2. Getting an OpenGL 3.0 context was never tried.

3. Context creation for ES 3.0 was failing on my machine. Since ES 2.0
looks like the intended version from the surrounding code, I set it to
that. It could be rewritten to use a similar loop as standard OpenGL and
try from the highest version to the lowest.

BUG=skia:5403
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2147513002
==========

to

==========
Fix context creation problems in dm

Fixes these issues:

1. The glXCreateContextAttribsARB call seems to modify the
context_attrib parameter upon failure. Since context_attrib was static,
if it first tried to create an OpenGL 4.4 context and it failed, further
attempts to create a context with lower versions would also fail.

2. Getting an OpenGL 3.0 context was never tried.

3. Context creation for ES 3.0 was failing on my machine. Since ES 2.0
looks like the intended version from the surrounding code, I set it to
that. It could be rewritten to use a similar loop as standard OpenGL and
try from the highest version to the lowest.

BUG=skia:5403
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2147513002

Committed:
https://skia.googlesource.com/skia/+/7b70156334629c083040f4d175e23b8743f53153
==========

[commit-bot: I haz the power, 2016-07-20 14:01:49]

Committed patchset #3 (id:40001) as
https://skia.googlesource.com/skia/+/7b70156334629c083040f4d175e23b8743f53153