Fix ResourceLoadTiming Resolution Issue 3rd step - remove old fields

Source/core/page/PerformanceResourceTiming.h

Index: Source/core/page/PerformanceResourceTiming.h
diff --git a/Source/core/page/PerformanceResourceTiming.h b/Source/core/page/PerformanceResourceTiming.h
index dad907ef9219252ce813fae335d34cff1b5790ac..4a7848af6baf0e044b6e6f942d3fb4bf15b0e896 100644
--- a/Source/core/page/PerformanceResourceTiming.h
+++ b/Source/core/page/PerformanceResourceTiming.h
@@ -72,10 +72,6 @@ private:
     PerformanceResourceTiming(const AtomicString& initatorType, const ResourceRequest&, const ResourceResponse&, double initiationTime, double finishTime, Document*);
     ~PerformanceResourceTiming();
 
-#ifndef ENABLE_DOUBLE_RESOURCE_LOAD_TIMING
-    double resourceTimeToDocumentMilliseconds(int deltaMilliseconds) const;
-#endif
-
     AtomicString m_initiatorType;
     RefPtr<ResourceLoadTiming> m_timing;
     double m_finishTime;