Use std::isnan instead of isnan in global ns

third_party/WebKit/Source/platform/PlatformTouchPoint.h

Index: third_party/WebKit/Source/platform/PlatformTouchPoint.h
diff --git a/third_party/WebKit/Source/platform/PlatformTouchPoint.h b/third_party/WebKit/Source/platform/PlatformTouchPoint.h
index e806327f43fe066fed9d2ea34a9ac33e0e8a13df..b9071f1534b93d731d72dfe5655f0edb45c42e19 100644
--- a/third_party/WebKit/Source/platform/PlatformTouchPoint.h
+++ b/third_party/WebKit/Source/platform/PlatformTouchPoint.h
@@ -49,7 +49,7 @@ public:
     FloatPoint pos() const { return m_pos; }
     FloatSize radius() const { return m_radius; }
     float rotationAngle() const { return m_rotationAngle; }
-    float force() const { ASSERT(!isnan(pointerProperties().force)); return pointerProperties().force; }
+    float force() const { ASSERT(!std::isnan(pointerProperties().force)); return pointerProperties().force; }
 
 protected:
     WebPointerProperties m_pointerProperties;