Use nullptr_t for RefPtr, PassRefPtr and RawPtr.

Source/core/timing/ResourceTimingInfo.h

Index: Source/core/timing/ResourceTimingInfo.h
diff --git a/Source/core/timing/ResourceTimingInfo.h b/Source/core/timing/ResourceTimingInfo.h
index a3784a63e59da6f6bff6bbdd34a104255507a86b..ef3f42dc0ea80db761aa8c052730ba39733aa953 100644
--- a/Source/core/timing/ResourceTimingInfo.h
+++ b/Source/core/timing/ResourceTimingInfo.h
@@ -63,9 +63,9 @@ public:
 
     void clearLoadTimings()
     {
-        m_finalResponse.setResourceLoadTiming(0);
+        m_finalResponse.setResourceLoadTiming(nullptr);
         for (size_t i = 0; i < m_redirectChain.size(); ++i)
-            m_redirectChain[i].setResourceLoadTiming(0);
+            m_redirectChain[i].setResourceLoadTiming(nullptr);
     }
 
 private: