Fix cpplint whitespace/comments issues

Change-Id: Iae286862c85fb8fd8901eae1204cd6d271d69496
diff --git a/runtime/reference_table.cc b/runtime/reference_table.cc
index 192535a..de64c26 100644
--- a/runtime/reference_table.cc
+++ b/runtime/reference_table.cc
@@ -232,7 +232,7 @@
 }
 
 void ReferenceTable::VisitRoots(RootVisitor* visitor, void* arg) {
-  typedef Table::const_iterator It; // TODO: C++0x auto
+  typedef Table::const_iterator It;  // TODO: C++0x auto
   for (It it = entries_.begin(), end = entries_.end(); it != end; ++it) {
     visitor(*it, arg);
   }