Cleanup GrGLInterface after Chromium changes

Depends on landing https://codereview.chromium.org/143263014

R=robertphillips@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/149533002

git-svn-id: http://skia.googlecode.com/svn/trunk@13630 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/debug/GrGLCreateDebugInterface.cpp b/src/gpu/gl/debug/GrGLCreateDebugInterface.cpp
index a9cc34a..2751e02 100644
--- a/src/gpu/gl/debug/GrGLCreateDebugInterface.cpp
+++ b/src/gpu/gl/debug/GrGLCreateDebugInterface.cpp
@@ -919,5 +919,8 @@
     functions->fBindFragDataLocationIndexed =
                                     noOpGLBindFragDataLocationIndexed;
 
+    interface->fExtensions.init(kGL_GrGLStandard, functions->fGetString, functions->fGetStringi,
+                                functions->fGetIntegerv);
+
     return interface;
 }