Oilpan: fix building with blink_gc_profiling:1

Source/platform/heap/ThreadState.cpp

Index: Source/platform/heap/ThreadState.cpp
diff --git a/Source/platform/heap/ThreadState.cpp b/Source/platform/heap/ThreadState.cpp
index cd9b8ece825968d398643ef089d43ba0138c1954..f7bee8ce16c2d34cb1f0cb8b76b983f3f05619c8 100644
--- a/Source/platform/heap/ThreadState.cpp
+++ b/Source/platform/heap/ThreadState.cpp
@@ -446,7 +446,7 @@ void ThreadState::snapshot()
 
     Vector<String> classNameVector(info.classTags.size());
     for (SnapshotInfo::ClassTagMap::iterator it = info.classTags.begin(); it != info.classTags.end(); ++it)
-        classNameVector[it->value] = it->key->m_className;
+        classNameVector[it->value] = it->key->className();
 
     size_t liveSize = 0;
     size_t deadSize = 0;