Fix ResourceLoadTiming resolution lose issue.

Source/core/platform/network/ResourceLoadTiming.cpp

 /*
  * Copyright (C) 2011 Google, 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 10 matching lines @@
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (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/platform/network/ResourceLoadTiming.h"
 
 namespace WebCore {
 
+#ifndef ENABLE_DOUBLE_RESOURCE_LOAD_TIMING
 double ResourceLoadTiming::convertResourceLoadTimeToMonotonicTime(int deltaMilliseconds) const
 {
     return requestTime + deltaMilliseconds / 1000.0;
 }
+#endif
 
 }