Revert of Prefer to use the OES_depth24 extension for WebGL's depth-only back buffers.

Revert of Prefer to use the OES_depth24 extension for WebGL's depth-only back buffers. (patchset #5 id:80001 of https://codereview.chromium.org/1675973002/ )

Reason for revert:
Speculative revert: appears to break printing/webgl-oversized-printing.html on Linux MSAN: https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20MSAN/builds/8511

Original issue's description:
> Prefer to use the OES_depth24 extension for WebGL's depth-only back buffers.
> 
> Instead of using the OES_packed_depth_stencil extension to obtain 24-bit
> depth buffers, prefer the OES_depth24 extension. This avoids a situation
> where the depth buffer is cleared but the stencil buffer must be
> preserved, leading to performance problems on some GPUs.
> 
> BUG=584807
> 
> Committed: https://crrev.com/2374479265b26ba0a4a658582b068a4526220774
> Cr-Commit-Position: refs/heads/master@{#374562}

TBR=bajones@chromium.org,zmo@chromium.org,marcheu@chromium.org,kbr@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=584807

[phoglund_chromium, 2016-02-16 10:15:41]

Created Revert of Prefer to use the OES_depth24 extension for WebGL's depth-only
back buffers.

[commit-bot: I haz the power, 2016-02-16 10:16:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1698883004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1698883004/1

[commit-bot: I haz the power, 2016-02-16 10:18:42]

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

[commit-bot: I haz the power, 2016-02-16 10:18:43]

Try jobs failed on following builders:
  ios_rel_device_ninja on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ni...)
  mac_chromium_gn_rel on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_gn_r...)
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[phoglund_chromium, 2016-02-16 10:39:49]

On 2016/02/16 10:18:43, commit-bot: I haz the power wrote:
> Try jobs failed on following builders:
>   ios_rel_device_ninja on tryserver.chromium.mac (JOB_FAILED,
>
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ni...)
>   mac_chromium_gn_rel on tryserver.chromium.mac (JOB_FAILED,
>
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_gn_r...)
>   mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
>
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

Ok, that didn't work. I guess I have to revert some other patch first...

[phoglund_chromium, 2016-02-16 11:47:27]

On 2016/02/16 10:39:49, phoglund_chrome wrote:
> On 2016/02/16 10:18:43, commit-bot: I haz the power wrote:
> > Try jobs failed on following builders:
> >   ios_rel_device_ninja on tryserver.chromium.mac (JOB_FAILED,
> >
>
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ni...)
> >   mac_chromium_gn_rel on tryserver.chromium.mac (JOB_FAILED,
> >
>
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_gn_r...)
> >   mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
> >
>
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)
> 
> Ok, that didn't work. I guess I have to revert some other patch first...

https://codereview.chromium.org/1698303002/ reverts both patches, closing this
one...

[phoglund_chromium, 2016-02-16 11:47:37]

Description was changed from

==========
Revert of Prefer to use the OES_depth24 extension for WebGL's depth-only back
buffers. (patchset #5 id:80001 of https://codereview.chromium.org/1675973002/ )

Reason for revert:
Speculative revert: appears to break printing/webgl-oversized-printing.html on
Linux MSAN:
https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20MSAN/b...

Original issue's description:
> Prefer to use the OES_depth24 extension for WebGL's depth-only back buffers.
> 
> Instead of using the OES_packed_depth_stencil extension to obtain 24-bit
> depth buffers, prefer the OES_depth24 extension. This avoids a situation
> where the depth buffer is cleared but the stencil buffer must be
> preserved, leading to performance problems on some GPUs.
> 
> BUG=584807
> 
> Committed: https://crrev.com/2374479265b26ba0a4a658582b068a4526220774
> Cr-Commit-Position: refs/heads/master@{#374562}

TBR=bajones@chromium.org,zmo@chromium.org,marcheu@chromium.org,kbr@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=584807
==========

to

==========
Revert of Prefer to use the OES_depth24 extension for WebGL's depth-only back
buffers. (patchset #5 id:80001 of https://codereview.chromium.org/1675973002/ )

Reason for revert:
Speculative revert: appears to break printing/webgl-oversized-printing.html on
Linux MSAN:
https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20MSAN/b...

Original issue's description:
> Prefer to use the OES_depth24 extension for WebGL's depth-only back buffers.
> 
> Instead of using the OES_packed_depth_stencil extension to obtain 24-bit
> depth buffers, prefer the OES_depth24 extension. This avoids a situation
> where the depth buffer is cleared but the stencil buffer must be
> preserved, leading to performance problems on some GPUs.
> 
> BUG=584807
> 
> Committed: https://crrev.com/2374479265b26ba0a4a658582b068a4526220774
> Cr-Commit-Position: refs/heads/master@{#374562}

TBR=bajones@chromium.org,zmo@chromium.org,marcheu@chromium.org,kbr@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=584807
==========