Use glGetStringi to get extensions when available.

src/gpu/gl/GrGLDefines.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 
 #ifndef GrGLDefines_DEFINED
 #define GrGLDefines_DEFINED
 
+/* Profiles */
+#define GR_GL_CONTEXT_PROFILE_MASK              0x9126
+#define GR_GL_CONTEXT_CORE_PROFILE_BIT          0x00000001
+#define GR_GL_CONTEXT_COMPATIBILITY_PROFILE_BIT 0x00000002
+
 // The following constants consist of the intersection of GL constants
 // exported by GLES 1.0, GLES 2.0, and desktop GL required by the system.
 
 #define GR_GL_DEPTH_BUFFER_BIT               0x00000100
 #define GR_GL_STENCIL_BUFFER_BIT             0x00000400
 #define GR_GL_COLOR_BUFFER_BIT               0x00004000
 
 /* Boolean */
 #define GR_GL_FALSE                          0
 #define GR_GL_TRUE                           1
@@ skipping 326 matching lines @@
 #define GR_GL_INVERT                         0x150A
 #define GR_GL_INCR_WRAP                      0x8507
 #define GR_GL_DECR_WRAP                      0x8508
 
 /* StringName */
 #define GR_GL_VENDOR                         0x1F00
 #define GR_GL_RENDERER                       0x1F01
 #define GR_GL_VERSION                        0x1F02
 #define GR_GL_EXTENSIONS                     0x1F03
 
+/* StringCounts */
+#define GR_GL_NUM_EXTENSIONS                 0x821D
+
 /* Pixel Mode / Transfer */
 #define GR_GL_UNPACK_ROW_LENGTH              0x0CF2
 #define GR_GL_PACK_ROW_LENGTH                0x0D02
 
 
 /* TextureMagFilter */
 #define GR_GL_NEAREST                        0x2600
 #define GR_GL_LINEAR                         0x2601
 
 /* TextureMinFilter */
@@ skipping 494 matching lines @@
 #define GR_GL_ADJACENT_PAIRS                                0x90AE
 #define GR_GL_FIRST_TO_REST                                 0x90AF
 
 //path gen modes
 #define GR_GL_PATH_GEN_MODE                                 0x90B0
 #define GR_GL_PATH_GEN_COEFF                                0x90B1
 #define GR_GL_PATH_GEN_COLOR_FORMAT                         0x90B2
 #define GR_GL_PATH_GEN_COMPONENTS                           0x90B3
 
 #endif