Add GL_CHROMIUM_screen_space_antialiasing to support alternative AA
MSAA is very expensive on some platforms. We introduce extention
GL_CHROMIUM_screen_space_antialiasing to support other antialiasing
approach. It will perform antialiasing to the color attachments of
the currently bound draw framebuffer. As an example, we implement it
using GL_INTEL_framebuffer_CMAA which results in similar quality of
MSAA at better performance.
The blink side change is in below link:
https://codereview.chromium.org/1301923002
BUG=524285
Review URL: https://codereview.chromium.org/1298523003
Cr-Commit-Position: refs/heads/master@{#348412}
33 files changed
