Remove duplicated headers from core/

Source/core/timing/Performance.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 17 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/timing/Performance.h"
 
 #include "core/dom/Document.h"
 #include "core/loader/DocumentLoader.h"
 #include "core/timing/ResourceTimingInfo.h"
-#include "core/timing/MemoryInfo.h"
-#include "core/timing/PerformanceEntry.h"
-#include "core/timing/PerformanceNavigation.h"
 #include "core/timing/PerformanceResourceTiming.h"
-#include "core/timing/PerformanceTiming.h"
 #include "core/timing/PerformanceUserTiming.h"
 #include "platform/weborigin/SecurityOrigin.h"
 #include "wtf/CurrentTime.h"
 
 #include "core/frame/Frame.h"
 
 namespace WebCore {
 
 static const size_t defaultResourceTimingBufferSize = 150;
 
@@ skipping 222 matching lines @@
         m_userTiming = UserTiming::create(this);
     m_userTiming->clearMeasures(measureName);
 }
 
 double Performance::now() const
 {
     return 1000.0 * (monotonicallyIncreasingTime() - m_referenceTime);
 }
 
 } // namespace WebCore