Rename GR_GL_GET_PROC macros in mesa and unix GrGLInterface factories to be more consistent with other platforms.

R=robertphillips@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/258693008

git-svn-id: http://skia.googlecode.com/svn/trunk/src@14418 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed