Fix broken build due to missing interface definition.

Change-Id: Ifcdb6d43f6ee23e6d91d01dc4fe25140f2d3d870
diff --git a/gpu/src/android/GrGLDefaultInterface_android.cpp b/gpu/src/android/GrGLDefaultInterface_android.cpp
index 0a1f7eb..e52277e 100644
--- a/gpu/src/android/GrGLDefaultInterface_android.cpp
+++ b/gpu/src/android/GrGLDefaultInterface_android.cpp
@@ -126,7 +126,7 @@
     NULL,  // glResolveMultisampleFramebuffer
     glMapBufferOES,
     glUnmapBufferOES,
-
+    NULL,
     GrGLInterface::kStaticInitEndGuard
   };
   static bool host_StubGL_initialized = false;