Add optional per-gl-func client callback.
Review URL: http://codereview.appspot.com/4964055/



git-svn-id: http://skia.googlecode.com/svn/trunk@2207 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/src/GrGLIndexBuffer.cpp b/gpu/src/GrGLIndexBuffer.cpp
index 54ee78b..2791527 100644
--- a/gpu/src/GrGLIndexBuffer.cpp
+++ b/gpu/src/GrGLIndexBuffer.cpp
@@ -59,8 +59,10 @@
                            NULL,
                            this->dynamic() ? GR_GL_DYNAMIC_DRAW :
                                              GR_GL_STATIC_DRAW));
-        fLockPtr = GL_CALL(MapBuffer(GR_GL_ELEMENT_ARRAY_BUFFER,
-                                     GR_GL_WRITE_ONLY));
+        GR_GL_CALL_RET(GPUGL->glInterface(),
+                       fLockPtr,
+                       MapBuffer(GR_GL_ELEMENT_ARRAY_BUFFER,
+                                 GR_GL_WRITE_ONLY));
 
         return fLockPtr;
     }