gl_context_glx: add workaround to create default context

gl_context_glx: add workaround to create default context

On old Mesa and hardware combos, creating the highest context version
possible leads to incorrect rendering in WebGL. Add a workaround to
fallback to creating a default context.

BUG=659030
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2467103003
Cr-Commit-Position: refs/heads/master@{#429786}
(cherry picked from commit e8b4248621c4ed428eec4036f4918185cea23cd6)

Committed: https://chromium.googlesource.com/chromium/src/+/84059adde3bf2263c0bf554d8dfbaac91a99ae70

[Ken Russell (switch to Gerrit), 2016-11-07 23:45:09]

Description was changed from

==========
gl_context_glx: add workaround to create default context

On old Mesa and hardware combos, creating the highest context version
possible leads to incorrect rendering in WebGL. Add a workaround to
fallback to creating a default context.

BUG=659030
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2467103003
Cr-Commit-Position: refs/heads/master@{#429786}
(cherry picked from commit e8b4248621c4ed428eec4036f4918185cea23cd6)
==========

to

==========
gl_context_glx: add workaround to create default context

On old Mesa and hardware combos, creating the highest context version
possible leads to incorrect rendering in WebGL. Add a workaround to
fallback to creating a default context.

BUG=659030
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2467103003
Cr-Commit-Position: refs/heads/master@{#429786}
(cherry picked from commit e8b4248621c4ed428eec4036f4918185cea23cd6)

Committed:
https://chromium.googlesource.com/chromium/src/+/84059adde3bf2263c0bf554d8dfb...
==========

[Ken Russell (switch to Gerrit), 2016-11-07 23:45:11]

Committed patchset #1 (id:1) manually as
84059adde3bf2263c0bf554d8dfbaac91a99ae70.