include RefCounted.h where needed, only.

third_party/WebKit/Source/core/timing/PerformanceBase.h

Index: third_party/WebKit/Source/core/timing/PerformanceBase.h
diff --git a/third_party/WebKit/Source/core/timing/PerformanceBase.h b/third_party/WebKit/Source/core/timing/PerformanceBase.h
index 7af201f4a1d51ae78bfeb6a65ec92c0708df06e0..0a1417d03aab3b1ac6aaa22f0074b8aa2451244b 100644
--- a/third_party/WebKit/Source/core/timing/PerformanceBase.h
+++ b/third_party/WebKit/Source/core/timing/PerformanceBase.h
@@ -38,9 +38,10 @@
 #include "core/timing/PerformanceEntry.h"
 #include "platform/Timer.h"
 #include "platform/heap/Handle.h"
-#include "wtf/RefCounted.h"
-#include "wtf/RefPtr.h"
-#include "wtf/text/WTFString.h"
+#include "wtf/Forward.h"
+#include "wtf/HashSet.h"
+#include "wtf/ListHashSet.h"
+#include "wtf/Vector.h"
 
 namespace blink {
 
@@ -111,8 +112,8 @@ public:
     DECLARE_VIRTUAL_TRACE();
 
 protected:
-
     explicit PerformanceBase(double timeOrigin);
+
     bool isResourceTimingBufferFull();
     void addResourceTimingBuffer(PerformanceEntry&);