Add glCopyTexSubImage2D to GrGLInterface

Author: bsalomon@google.com

Reviewed By: robertphillips@google.com

Review URL: https://chromiumcodereview.appspot.com/13941006

git-svn-id: http://skia.googlecode.com/svn/trunk@8634 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/mesa/GrGLCreateMesaInterface.cpp b/src/gpu/gl/mesa/GrGLCreateMesaInterface.cpp
index 6ccd9fa..55f4409 100644
--- a/src/gpu/gl/mesa/GrGLCreateMesaInterface.cpp
+++ b/src/gpu/gl/mesa/GrGLCreateMesaInterface.cpp
@@ -66,6 +66,7 @@
         GR_GL_GET_PROC(ColorMask);
         GR_GL_GET_PROC(CompileShader);
         GR_GL_GET_PROC(CompressedTexImage2D);
+        GR_GL_GET_PROC(CopyTexSubImage2D);
         GR_GL_GET_PROC(CreateProgram);
         GR_GL_GET_PROC(CreateShader);
         GR_GL_GET_PROC(CullFace);