Fix up TODO: c++0x, update cpplint.

Needed to update cpplint to handle const auto.

Fixed a few cpplint errors that were being missed before.

Replaced most of the TODO c++0x with ranged based loops. Loops which
do not have a descriptive container name have a concrete type instead
of auto.

Change-Id: Id7cc0f27030f56057c544e94277300b3f298c9c5
diff --git a/runtime/gc/collector/mark_sweep.h b/runtime/gc/collector/mark_sweep.h
index e39e2f7..8db03d3 100644
--- a/runtime/gc/collector/mark_sweep.h
+++ b/runtime/gc/collector/mark_sweep.h
@@ -428,6 +428,7 @@
 
   bool clear_soft_references_;
 
+ private:
   friend class AddIfReachesAllocSpaceVisitor;  // Used by mod-union table.
   friend class CheckBitmapVisitor;
   friend class CheckObjectVisitor;