Added CERES_ prefix to the DISALLOW macros.

Change-Id: Ib81e9112e8bbc6ed6cb52f21825df0f6e659be51
diff --git a/internal/ceres/graph.h b/internal/ceres/graph.h
index fd7a224..2c0f6d2 100644
--- a/internal/ceres/graph.h
+++ b/internal/ceres/graph.h
@@ -129,7 +129,7 @@
   HashMap<Vertex, HashSet<Vertex> > edges_;
   HashMap<pair<Vertex, Vertex>, double> edge_weights_;
 
-  DISALLOW_COPY_AND_ASSIGN(Graph);
+  CERES_DISALLOW_COPY_AND_ASSIGN(Graph);
 };
 
 }  // namespace internal