Rename kES2_GrGLBinding to kES_GrGLBinding. Step 0 for supporting ES3.

R=robertphillips@google.com

Review URL: https://codereview.chromium.org/23185004

git-svn-id: http://skia.googlecode.com/svn/trunk@10747 2bbb7eff-a529-9590-31e7-b0007b416f81
11 files changed