Update from https://crrev.com/315085

sky/engine/platform/SharedTimer.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "sky/engine/config.h"
 #include "sky/engine/platform/SharedTimer.h"
 
+#include <cmath>
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "sky/engine/wtf/CurrentTime.h"
 
 namespace blink {
 namespace {
 
 class SharedTimerImpl {
     WTF_MAKE_NONCOPYABLE(SharedTimerImpl);
 public:
@@ skipping 68 matching lines @@
 {
     SharedTimerImpl::instance().setSharedTimerFireInterval(interval);
 }
 
 void stopSharedTimer()
 {
     SharedTimerImpl::instance().stopSharedTimer();
 }
 
 } // namespace blink