fix: recalibrate simpleFullscreen when display metrics change (#28870)

shell/browser/native_window.h

@@ -201,6 +201,7 @@ class NativeWindow : public base::SupportsUserData,
   virtual void SetTrafficLightPosition(const gfx::Point& position) = 0;
   virtual gfx::Point GetTrafficLightPosition() const = 0;
   virtual void RedrawTrafficLights() = 0;
+  virtual void UpdateFrame() = 0;
 #endif
 
   // Touchbar API

shell/browser/native_window_mac.h

@@ -15,6 +15,7 @@
 
 #include "base/mac/scoped_nsobject.h"
 #include "shell/browser/native_window.h"
+#include "ui/display/display_observer.h"
 #include "ui/native_theme/native_theme_observer.h"
 #include "ui/views/controls/native/native_view_host.h"
 
@@ -28,7 +29,9 @@ namespace electron {
 
 class RootViewMac;
 
-class NativeWindowMac : public NativeWindow, public ui::NativeThemeObserver {
+class NativeWindowMac : public NativeWindow,
+                        public ui::NativeThemeObserver,
+                        public display::DisplayObserver {
  public:
   NativeWindowMac(const gin_helper::Dictionary& options, NativeWindow* parent);
   ~NativeWindowMac() override;
@@ -130,7 +133,6 @@ class NativeWindowMac : public NativeWindow, public ui::NativeThemeObserver {
   bool IsVisibleOnAllWorkspaces() override;
 
   void SetAutoHideCursor(bool auto_hide) override;
-
   void SelectPreviousTab() override;
   void SelectNextTab() override;
   void MergeAllWindows() override;
@@ -141,6 +143,7 @@ class NativeWindowMac : public NativeWindow, public ui::NativeThemeObserver {
   bool SetWindowButtonVisibility(bool visible) override;
 
   void SetVibrancy(const std::string& type) override;
+  void UpdateFrame() override;
   void SetTouchBar(
       std::vector<gin_helper::PersistentDictionary> items) override;
   void RefreshTouchBarItem(const std::string& item_id) override;
@@ -195,6 +198,10 @@ class NativeWindowMac : public NativeWindow, public ui::NativeThemeObserver {
   bool CanResize() const override;
   views::View* GetContentsView() override;
 
+  // display::DisplayObserver:
+  void OnDisplayMetricsChanged(const display::Display& display,
+                               uint32_t changed_metrics) override;
+
  private:
   // Add custom layers to the content view.
   void AddContentViewLayers(bool minimizable, bool closable);

shell/browser/native_window_mac.mm

@@ -38,6 +38,7 @@
 #include "shell/common/process_util.h"
 #include "skia/ext/skia_utils_mac.h"
 #include "third_party/webrtc/modules/desktop_capture/mac/window_list_utils.h"
+#include "ui/display/screen.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gl/gpu_switching_manager.h"
 #include "ui/views/background.h"
@@ -350,6 +351,7 @@ void ViewDidMoveToSuperview(NSView* self, SEL _cmd) {
                                  NativeWindow* parent)
     : NativeWindow(options, parent), root_view_(new RootViewMac(this)) {
   ui::NativeTheme::GetInstanceForNativeUi()->AddObserver(this);
+  display::Screen::GetScreen()->AddObserver(this);
 
   int width = 800, height = 600;
   options.Get(options::kWidth, &width);
@@ -541,6 +543,7 @@ void ViewDidMoveToSuperview(NSView* self, SEL _cmd) {
 void NativeWindowMac::Cleanup() {
   DCHECK(!IsClosed());
   ui::NativeTheme::GetInstanceForNativeUi()->RemoveObserver(this);
+  display::Screen::GetScreen()->RemoveObserver(this);
   [NSEvent removeMonitor:wheel_event_monitor_];
 }
 
@@ -1116,6 +1119,17 @@ void ViewDidMoveToSuperview(NSView* self, SEL _cmd) {
   [window setExcludedFromWindowsMenu:excluded];
 }
 
+void NativeWindowMac::OnDisplayMetricsChanged(const display::Display& display,
+                                              uint32_t changed_metrics) {
+  // We only want to force screen recalibration if we're in simpleFullscreen
+  // mode.
+  if (!is_simple_fullscreen_)
+    return;
+
+  base::PostTask(FROM_HERE, {content::BrowserThread::UI},
+                 base::BindOnce(&NativeWindow::UpdateFrame, GetWeakPtr()));
+}
+
 void NativeWindowMac::SetSimpleFullScreen(bool simple_fullscreen) {
   NSWindow* window = GetNativeWindow().GetNativeNSWindow();
 
@@ -1667,6 +1681,13 @@ void ViewDidMoveToSuperview(NSView* self, SEL _cmd) {
   return traffic_light_position_;
 }
 
+// In simpleFullScreen mode, update the frame for new bounds.
+void NativeWindowMac::UpdateFrame() {
+  NSWindow* window = GetNativeWindow().GetNativeNSWindow();
+  NSRect fullscreenFrame = [window.screen frame];
+  [window setFrame:fullscreenFrame display:YES animate:YES];
+}
+
 void NativeWindowMac::SetTouchBar(
     std::vector<gin_helper::PersistentDictionary> items) {
   if (@available(macOS 10.12.2, *)) {