Add glTexGen funcs to interface

R=robertphillips@google.com

Author: bsalomon@google.com

Review URL: https://chromiumcodereview.appspot.com/23513006

git-svn-id: http://skia.googlecode.com/svn/trunk@11032 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/GrGLDefines.h b/src/gpu/gl/GrGLDefines.h
index 2ab9570..a843953 100644
--- a/src/gpu/gl/GrGLDefines.h
+++ b/src/gpu/gl/GrGLDefines.h
@@ -439,6 +439,7 @@
 #define GR_GL_TEXTURE31                      0x84DF
 #define GR_GL_ACTIVE_TEXTURE                 0x84E0
 #define GR_GL_MAX_TEXTURE_UNITS              0x84E2
+#define GR_GL_MAX_TEXTURE_COORDS             0x8871
 
 /* TextureWrapMode */
 #define GR_GL_REPEAT                         0x2901
@@ -464,6 +465,8 @@
 #define GR_GL_TEXTURE_ENV_COLOR             0x2201
 #define GR_GL_TEXTURE_GEN_S                 0x0C60
 #define GR_GL_TEXTURE_GEN_T                 0x0C61
+#define GR_GL_TEXTURE_GEN_R                 0x0C62
+#define GR_GL_TEXTURE_GEN_Q                 0x0C63
 #define GR_GL_TEXTURE_GEN_MODE              0x2500
 #define GR_GL_TEXTURE_BORDER_COLOR          0x1004
 #define GR_GL_TEXTURE_WIDTH                 0x1000