WPF - Rendering not refreshed at maximum framerate.

I noticed a strange behavior in the WPF CefSharp browser. When watching a video (YouTube for example), the video is not totaly fluid. but if something else is hapenning in the application, like an animation, the video is completly fluid.
My theory is that the animation cause WPF do redraw at 60 FPS and it cause the CefSharp browser to redraw at this rate. When no animation is running, the default CefSharp redraw rate is smalller.

I tried differents values for the `CefCommandLineArgs --off-screen-frame-rate` ( 25, 30 , 60, 120 ) but the result is the same.

I am using The WPF nuget version 63.0.0 on WIndows 10.
I use the following command line
```
settings.CefCommandLineArgs.Add("enable-gpu", "1");
settings.CefCommandLineArgs.Add("enable-webgl", "1");
settings.CefCommandLineArgs.Add("enable-begin-frame-scheduling", "1");
settings.CefCommandLineArgs.Add("--off-screen-frame-rate", "60");
```
with gpu disabled, the result is the same.