private void Init(Rect buttonRect)
{
buttonRect = GUIUtility.GUIToScreenRect(buttonRect);
this.CalcValidLayers();
int num = ((this.s_LayerNames.Count + 2) + 1) + 1;
float a = (num * 16f) + 6f;
int sortingLayerCount = InternalEditorUtility.GetSortingLayerCount();
if (sortingLayerCount > 1)
{
a += 22f;
a += sortingLayerCount * 16f;
}
this.m_ContentHeight = a;
a += 2f;
a = Mathf.Min(a, 600f);
Vector2 windowSize = new Vector2(180f, a);
base.ShowAsDropDown(buttonRect, windowSize);
}