Use OPENGL macros to be more clear about which OpenGL/ES WebGL uses on Cocoa
<rdar://problem/37507669>
Created attachment 334081 [details] Patch
Comment on attachment 334081 [details] Patch r=me if EWS is happy
Created attachment 334088 [details] Patch
Committed r228590: <https://trac.webkit.org/changeset/228590>
Comment on attachment 334088 [details] Patch Clearing r? flag.