The type or namespace name `Profiling' does not exist in the namespace `UnityEngine'. Are you missing an assembly reference?

I got the error when I want to import leapMotion core Assets package into unity .

Assets/LeapMotion/Core/Scripts/Utils/ProfilerSample.cs(11,19): error CS0234: The type or namespace name ‘Profiling’ does not exist in the namespace ‘UnityEngine’. Are you missing an assembly reference?

what do I do to solve the problem?

Try importing the following namespace:

using UnityEngine.Profiling;