ソースコード

using System.Reflection;
using UnityEditor;
using UnityEngine;

[InitializeOnLoad]
public static class Example
{
    static Example()
    {
        Editor.finishedDefaultHeaderGUI += OnGUI;
    }

    private static void OnGUI( Editor editor )
    {
        EditorGUILayout.BeginHorizontal();

        if ( GUILayout.Button( "Lock" ) )
        {
            var tracker = ActiveEditorTracker.sharedTracker;
            tracker.isLocked = !tracker.isLocked;
            tracker.ForceRebuild();
        }

        if ( GUILayout.Button( "Debug" ) )
        {
            var window          = Resources.FindObjectsOfTypeAll<EditorWindow>();
            var inspectorWindow = ArrayUtility.Find( window, c => c.GetType().Name == "InspectorWindow" );

            if ( inspectorWindow == null ) return;

            var inspectorType = inspectorWindow.GetType();
            var tracker       = ActiveEditorTracker.sharedTracker;
            var isNormal      = tracker.inspectorMode == InspectorMode.Normal;
            var methodName    = isNormal ? "SetDebug" : "SetNormal";

            var attr       = BindingFlags.NonPublic | BindingFlags.Instance;
            var methodInfo = inspectorType.GetMethod( methodName, attr );
            methodInfo.Invoke( inspectorWindow, null );
            tracker.ForceRebuild();
        }

        EditorGUILayout.EndHorizontal();
    }
}

使用例