EditorWindowに好きなアイコンを付ける

IconTest_002.cs

using UnityEngine;
using UnityEditor;

public class IconTest_002 : EditorWindow {
	[MenuItem("window icon/icon2")]
	static void Init()
	{
		EditorWindow.GetWindow<IconTest_002>(false, "Firefox");
	}
}

IconTest_003_2.cs

using UnityEngine;
using UnityEditor;

public class IconTest_003_2 : EditorWindow {
	[MenuItem("window icon/icon3 2")]
	static void Init()
	{
		EditorWindow.GetWindow<IconTest_003_2>(false, "Windows 1");
	}
}