Fix variables names.

src/heap-profiler.h

Index: src/heap-profiler.h
diff --git a/src/heap-profiler.h b/src/heap-profiler.h
index bb7ca33d7a72f4ec15f03427a1cdac4536c049d6..23d9502c136ac5813f7c0480265e2caaece2fa35 100644
--- a/src/heap-profiler.h
+++ b/src/heap-profiler.h
@@ -208,10 +208,10 @@ class ClustersCoarser BASE_EMBEDDED {
   static const int kMaxPassesCount = 10;
 
   ZoneScope zscope_;
-  SimilarityList simList_;
-  EqualityTree eqTree_;
-  ClusterBackRefs* currentPair_;
-  JSObjectsClusterTree* currentSet_;
+  SimilarityList sim_list_;
+  EqualityTree eq_tree_;
+  ClusterBackRefs* current_pair_;
+  JSObjectsClusterTree* current_set_;
 };