Implement EXT_draw_buffers WebGL extention support in command buffer.
A few things:
1) I only hooked up with desktop GL backend, i.e., GL_ARB_draw_buffers. Will add GLES support later.
2) Probably we need to do something to enable this for Pepper3D also? If yes, will do so in a seperate CL.
3) I didn't add the wordarounds for Mac/Linux driver bugs. Will do so in a seperate CL.
BUG=180397
TEST=gpu_unittests, webgl conformance tests
Review URL: https://codereview.chromium.org/12545014
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@188129 0039d316-1c4b-4281-b951-d872f2087c98
39 files changed
