Throttle tooltip window rendering

Source/Engine/Platform/Base/WindowBase.h

@@ -298,7 +298,7 @@ public:
     /// <summary>
     /// The rendering task for that window.
     /// </summary>
-    RenderTask* RenderTask;
+    API_FIELD() RenderTask* RenderTask;
 
     /// <summary>
     /// Event fired when window gets shown.

Source/Engine/UI/GUI/Tooltip.cs

@@ -102,6 +102,9 @@ namespace FlaxEngine.GUI
             Visible = true;
             _window.Show();
             _showTarget.OnTooltipShown(this);
+
+            // Throttle tooltip rendering
+            _window.RenderTask.RenderFPS = 2;
         }
 
         /// <summary>