fix: disabling and enabling resizability on macOS (#31013)

Co-authored-by: Shelley Vohr <[email protected]>

shell/browser/native_window_mac.h

@@ -192,6 +192,7 @@ class NativeWindowMac : public NativeWindow,
  protected:
   // views::WidgetDelegate:
   views::View* GetContentsView() override;
+  bool CanMaximize() const override;
 
   // ui::NativeThemeObserver:
   void OnNativeThemeUpdated(ui::NativeTheme* observed_theme) override;

shell/browser/native_window_mac.mm

@@ -1714,31 +1714,35 @@ void NativeWindowMac::SetStyleMask(bool on, NSUInteger flag) {
   // we explicitly disable resizing while setting it.
   ScopedDisableResize disable_resize;
 
-  bool was_maximizable = IsMaximizable();
   if (on)
     [window_ setStyleMask:[window_ styleMask] | flag];
   else
     [window_ setStyleMask:[window_ styleMask] & (~flag)];
+
   // Change style mask will make the zoom button revert to default, probably
   // a bug of Cocoa or macOS.
-  SetMaximizable(was_maximizable);
+  SetMaximizable(maximizable_);
 }
 
 void NativeWindowMac::SetCollectionBehavior(bool on, NSUInteger flag) {
-  bool was_maximizable = IsMaximizable();
   if (on)
     [window_ setCollectionBehavior:[window_ collectionBehavior] | flag];
   else
     [window_ setCollectionBehavior:[window_ collectionBehavior] & (~flag)];
+
   // Change collectionBehavior will make the zoom button revert to default,
   // probably a bug of Cocoa or macOS.
-  SetMaximizable(was_maximizable);
+  SetMaximizable(maximizable_);
 }
 
 views::View* NativeWindowMac::GetContentsView() {
   return root_view_.get();
 }
 
+bool NativeWindowMac::CanMaximize() const {
+  return maximizable_;
+}
+
 void NativeWindowMac::OnNativeThemeUpdated(ui::NativeTheme* observed_theme) {
   base::PostTask(
       FROM_HERE, {content::BrowserThread::UI},

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

@@ -3682,6 +3682,18 @@ describe('BrowserWindow module', () => {
         }
       });
 
+      // On Linux there is no "resizable" property of a window.
+      ifit(process.platform !== 'linux')('does affect maximizability when disabled and enabled', () => {
+        const w = new BrowserWindow({ show: false });
+        expect(w.resizable).to.be.true('resizable');
+
+        expect(w.maximizable).to.be.true('maximizable');
+        w.resizable = false;
+        expect(w.maximizable).to.be.false('not maximizable');
+        w.resizable = true;
+        expect(w.maximizable).to.be.true('maximizable');
+      });
+
       ifit(process.platform === 'win32')('works for a window smaller than 64x64', () => {
         const w = new BrowserWindow({
           show: false,