Add EXT suffix to EXT_map_buffer_range references

This rearranges the code to use the non-suffixed entry point for ES
3.x contexts, and the suffixed entry point on ES 2.0 contexts that
have the extension.

R=robertphillips@google.com

Review URL: https://codereview.chromium.org/293993010

git-svn-id: http://skia.googlecode.com/svn/trunk@14823 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed