Update from https://crrev.com/315085

sky/engine/platform/network/ResourceResponse.cpp

 /*
  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009 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
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * 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 "sky/engine/config.h"
 #include "sky/engine/platform/network/ResourceResponse.h"
 
+#include <cmath>
 #include "sky/engine/wtf/CurrentTime.h"
 #include "sky/engine/wtf/StdLibExtras.h"
 
 namespace blink {
 
 ResourceResponse::ResourceResponse()
     : m_expectedContentLength(0)
     , m_httpStatusCode(0)
     , m_lastModifiedDate(0)
     , m_wasCached(false)
@@ skipping 399 matching lines @@
     if (a.httpHeaderFields() != b.httpHeaderFields())
         return false;
     if (a.resourceLoadTiming() && b.resourceLoadTiming() && *a.resourceLoadTiming() == *b.resourceLoadTiming())
         return true;
     if (a.resourceLoadTiming() != b.resourceLoadTiming())
         return false;
     return true;
 }
 
 }