Use glGetStringi to get extensions when available.

src/gpu/gl/unix/GrGLCreateNativeInterface_unix.cpp

Index: src/gpu/gl/unix/GrGLCreateNativeInterface_unix.cpp
===================================================================
--- src/gpu/gl/unix/GrGLCreateNativeInterface_unix.cpp	(revision 7868)
+++ src/gpu/gl/unix/GrGLCreateNativeInterface_unix.cpp	(working copy)
@@ -7,6 +7,7 @@
  */
 
 
+#include "gl/GrGLExtensions.h"
 #include "gl/GrGLInterface.h"
 #include "../GrGLUtil.h"
 
@@ -22,10 +23,19 @@
 
 const GrGLInterface* GrGLCreateNativeInterface() {
     if (NULL != glXGetCurrentContext()) {
+
         const char* versionString = (const char*) glGetString(GL_VERSION);
-        const char* extString = (const char*) glGetString(GL_EXTENSIONS);
         GrGLVersion glVer = GrGLGetVersionFromString(versionString);
 
+        // This may or may not succeed depending on the gl version.
+        GrGLGetStringiProc glGetStringi =
+            (GrGLGetStringiProc) glXGetProcAddress(reinterpret_cast<const GLubyte*>("glGetStringi"));
+
+        GrGLExtensions extensions;
+        if (!extensions.init(kDesktop_GrGLBinding, glGetString, glGetStringi, glGetIntegerv)) {
+            return NULL;
+        }
+
         if (glVer < GR_GL_VER(1,5)) {
             // We must have array and element_array buffer objects.
             return NULL;
@@ -43,8 +53,8 @@
         interface->fBlendFunc = glBlendFunc;
 
         if (glVer >= GR_GL_VER(1,4) ||
-            GrGLHasExtensionFromString("GL_ARB_imaging", extString) ||
-            GrGLHasExtensionFromString("GL_EXT_blend_color", extString)) {
+            extensions.has("GL_ARB_imaging") ||
+            extensions.has("GL_EXT_blend_color")) {
             GR_GL_GET_PROC(BlendColor);
         }
 
@@ -83,12 +93,11 @@
         interface->fGetIntegerv = glGetIntegerv;
         GR_GL_GET_PROC(GetQueryObjectiv);
         GR_GL_GET_PROC(GetQueryObjectuiv);
-        if (glVer >= GR_GL_VER(3,3) ||
-            GrGLHasExtensionFromString("GL_ARB_timer_query", extString)) {
+        if (glVer >= GR_GL_VER(3,3) || extensions.has("GL_ARB_timer_query")) {
             GR_GL_GET_PROC(GetQueryObjecti64v);
             GR_GL_GET_PROC(GetQueryObjectui64v);
             GR_GL_GET_PROC(QueryCounter);
-        } else if (GrGLHasExtensionFromString("GL_EXT_timer_query", extString)) {
+        } else if (extensions.has("GL_EXT_timer_query")) {
             GR_GL_GET_PROC_SUFFIX(GetQueryObjecti64v, EXT);
             GR_GL_GET_PROC_SUFFIX(GetQueryObjectui64v, EXT);
         }
@@ -98,6 +107,7 @@
         GR_GL_GET_PROC(GetShaderInfoLog);
         GR_GL_GET_PROC(GetShaderiv);
         interface->fGetString = glGetString;
+        GR_GL_GET_PROC(GetStringi);
         interface->fGetTexLevelParameteriv = glGetTexLevelParameteriv;
         GR_GL_GET_PROC(GenQueries);
         interface->fGenTextures = glGenTextures;
@@ -108,8 +118,7 @@
         interface->fPixelStorei = glPixelStorei;
         interface->fReadBuffer = glReadBuffer;
         interface->fReadPixels = glReadPixels;
-        if (GrGLHasExtensionFromString("GL_NV_framebuffer_multisample_coverage",
-                                       extString)) {
+        if (extensions.has("GL_NV_framebuffer_multisample_coverage")) {
             GR_GL_GET_PROC_SUFFIX(RenderbufferStorageMultisampleCoverage, NV);
         }
         interface->fScissor = glScissor;
@@ -123,10 +132,9 @@
         interface->fTexImage2D = glTexImage2D;
         interface->fTexParameteri = glTexParameteri;
         interface->fTexParameteriv = glTexParameteriv;
-        if (glVer >= GR_GL_VER(4,2) ||
-            GrGLHasExtensionFromString("GL_ARB_texture_storage", extString)) {
+        if (glVer >= GR_GL_VER(4,2) || extensions.has("GL_ARB_texture_storage")) {
             GR_GL_GET_PROC(TexStorage2D);
-        } else if (GrGLHasExtensionFromString("GL_EXT_texture_storage", extString)) {
+        } else if (extensions.has("GL_EXT_texture_storage")) {
             GR_GL_GET_PROC_SUFFIX(TexStorage2D, EXT);
         }
         interface->fTexSubImage2D = glTexSubImage2D;
@@ -158,9 +166,7 @@
 
         // First look for GL3.0 FBO or GL_ARB_framebuffer_object (same since
         // GL_ARB_framebuffer_object doesn't use ARB suffix.)
-        if (glVer >= GR_GL_VER(3,0) ||
-            GrGLHasExtensionFromString("GL_ARB_framebuffer_object",
-                                       extString)) {
+        if (glVer >= GR_GL_VER(3,0) || extensions.has("GL_ARB_framebuffer_object")) {
             GR_GL_GET_PROC(GenFramebuffers);
             GR_GL_GET_PROC(GetFramebufferAttachmentParameteriv);
             GR_GL_GET_PROC(GetRenderbufferParameteriv);
@@ -175,8 +181,7 @@
             GR_GL_GET_PROC(BindRenderbuffer);
             GR_GL_GET_PROC(RenderbufferStorageMultisample);
             GR_GL_GET_PROC(BlitFramebuffer);
-        } else if (GrGLHasExtensionFromString("GL_EXT_framebuffer_object",
-                                              extString)) {
+        } else if (extensions.has("GL_EXT_framebuffer_object")) {
             GR_GL_GET_PROC_SUFFIX(GenFramebuffers, EXT);
             GR_GL_GET_PROC_SUFFIX(GetFramebufferAttachmentParameteriv, EXT);
             GR_GL_GET_PROC_SUFFIX(GetRenderbufferParameteriv, EXT);
@@ -189,12 +194,10 @@
             GR_GL_GET_PROC_SUFFIX(DeleteRenderbuffers, EXT);
             GR_GL_GET_PROC_SUFFIX(FramebufferRenderbuffer, EXT);
             GR_GL_GET_PROC_SUFFIX(BindRenderbuffer, EXT);
-            if (GrGLHasExtensionFromString("GL_EXT_framebuffer_multisample",
-                                             extString)) {
+            if (extensions.has("GL_EXT_framebuffer_multisample")) {
                 GR_GL_GET_PROC_SUFFIX(RenderbufferStorageMultisample, EXT);
             }
-            if (GrGLHasExtensionFromString("GL_EXT_framebuffer_blit",
-                                             extString)) {
+            if (extensions.has("GL_EXT_framebuffer_blit")) {
                 GR_GL_GET_PROC_SUFFIX(BlitFramebuffer, EXT);
             }
         } else {