Adjust workaround for mipmap-related OpenGL implementation bug on Mac OS X.

Adjust workaround for mipmap-related OpenGL implementation bug on Mac OS X.

BUG=101105
TEST=manually ran WebGL conformance test textures/texture-mips.html on NVIDIA and AMD GPUs on Mac OS
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=106634

[Ken Russell (switch to Gerrit), 2011-10-20 23:15:15]

Please review. Thanks.

[greggman, 2011-10-20 23:27:37]

http://codereview.chromium.org/8365018/diff/1/gpu/command_buffer/service/gles...
File gpu/command_buffer/service/gles2_cmd_decoder.cc (right):

http://codereview.chromium.org/8365018/diff/1/gpu/command_buffer/service/gles...
gpu/command_buffer/service/gles2_cmd_decoder.cc:3015: glTexParameteri(target,
GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
It seems like there are 2 possibliies

1) The state needs to be GL_NEAREST_MIPMAP_NEAREST
2) The state needs to be dirty

If it's #2 this won't fix it in certain cases. That seems easy to test

genTex
bindTex
texParm(GL_NEAREST_MIPMAP_NEAREST
texImage2d(red
genMips
texImage2d(blue
genMips

should we test that?

[greggman, 2011-10-20 23:33:28]

added that test. it passes
https://cvs.khronos.org/svn/repos/registry/trunk/public/webgl/sdk/tests/confo...

lgtm

[Ken Russell (switch to Gerrit), 2011-10-20 23:36:24]

http://codereview.chromium.org/8365018/diff/1/gpu/command_buffer/service/gles...
File gpu/command_buffer/service/gles2_cmd_decoder.cc (right):

http://codereview.chromium.org/8365018/diff/1/gpu/command_buffer/service/gles...
gpu/command_buffer/service/gles2_cmd_decoder.cc:3015: glTexParameteri(target,
GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
I believe it's neither, but a third possibility: the filter mode needs to have
been changed from the default at least once, and also needs to be set to
something requiring mipmaps.