fix: make BrowserWindow#isFocused() return false when blur() is called

The isFocused() method on macOS works by checking if the selected
BrowserWindow is a key window. Unfortunately doesn't work well with
focus() and blur() because these weren't calling any macOS APIs that
would change the key status of the window. Hence, this changes the
implementation of blur() to call orderOut first, which removes the key
status of the window. Then when the orderBack function is called, it
moves the window to the back of its level in the screen list, without
changing the key window.

Fixes: #33732
Signed-off-by: Darshan Sen <raisinten@gmail.com>

shell/browser/native_window_mac.mm

@@ -506,6 +506,7 @@ void ViewDidMoveToSuperview(NSView* self, SEL _cmd) {
     [[NSApplication sharedApplication] activateIgnoringOtherApps:NO];
     [window_ makeKeyAndOrderFront:nil];
   } else {
+    [window_ orderOut:nil];
     [window_ orderBack:nil];
   }
 }

spec-main/api-browser-window-spec.ts

@@ -762,11 +762,73 @@ describe('BrowserWindow module', () => {
       });
     });
 
-    describe('BrowserWindow.blur()', () => {
-      it('removes focus from window', () => {
+    // TODO(RaisinTen): Make this work on Windows too.
+    // Refs: https://github.com/electron/electron/issues/20464.
+    ifdescribe(process.platform !== 'win32')('BrowserWindow.blur()', () => {
+      it('removes focus from window', async () => {
+        {
+          const focus = once(w, 'focus');
+          const show = once(w, 'show');
+          w.show();
+          await show;
+          await focus;
+        }
+        expect(w.isFocused()).to.equal(true);
         w.blur();
         expect(w.isFocused()).to.equal(false);
       });
+
+      it('transfers focus status to the next window', async () => {
+        const w1 = new BrowserWindow({ show: false });
+        const w2 = new BrowserWindow({ show: false });
+        const w3 = new BrowserWindow({ show: false });
+        {
+          const focus = once(w3, 'focus');
+          const show1 = once(w1, 'show');
+          const show2 = once(w2, 'show');
+          const show3 = once(w3, 'show');
+          w1.show();
+          w2.show();
+          w3.show();
+          await show1;
+          await show2;
+          await show3;
+          await focus;
+        }
+        expect(w1.isFocused()).to.equal(false);
+        expect(w2.isFocused()).to.equal(false);
+        expect(w3.isFocused()).to.equal(true);
+
+        w3.blur();
+        expect(w1.isFocused()).to.equal(false);
+        expect(w2.isFocused()).to.equal(true);
+        expect(w3.isFocused()).to.equal(false);
+
+        w2.blur();
+        expect(w1.isFocused()).to.equal(true);
+        expect(w2.isFocused()).to.equal(false);
+        expect(w3.isFocused()).to.equal(false);
+
+        w1.blur();
+        expect(w1.isFocused()).to.equal(false);
+        expect(w2.isFocused()).to.equal(false);
+        expect(w3.isFocused()).to.equal(true);
+
+        w1.focus();
+        expect(w1.isFocused()).to.equal(true);
+        expect(w2.isFocused()).to.equal(false);
+        expect(w3.isFocused()).to.equal(false);
+
+        w2.focus();
+        expect(w1.isFocused()).to.equal(false);
+        expect(w2.isFocused()).to.equal(true);
+        expect(w3.isFocused()).to.equal(false);
+
+        w3.focus();
+        expect(w1.isFocused()).to.equal(false);
+        expect(w2.isFocused()).to.equal(false);
+        expect(w3.isFocused()).to.equal(true);
+      });
     });
 
     describe('BrowserWindow.getFocusedWindow()', () => {