fix: CHECK when adding view as its own child (#42108)

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Shelley Vohr <shelley.vohr@gmail.com>

spec/api-view-spec.ts

@@ -1,3 +1,4 @@
+import { expect } from 'chai';
 import { closeWindow } from './lib/window-helpers';
 import { BaseWindow, View } from 'electron/main';
 
@@ -10,6 +11,15 @@ describe('View', () => {
 
   it('can be used as content view', () => {
     w = new BaseWindow({ show: false });
-    w.setContentView(new View());
+    const v = new View();
+    w.setContentView(v);
+    expect(w.contentView).to.equal(v);
+  });
+
+  it('will throw when added as a child to itself', () => {
+    w = new BaseWindow({ show: false });
+    expect(() => {
+      w.contentView.addChildView(w.contentView);
+    }).to.throw('A view cannot be added as its own child');
   });
 });