tor-browser

commit 9e9e4fadc7b4de74afc45e7e03198d0b14823fb6
parent 2d3eb0655bcdf9b67117a3f3fb36dd6c0a0ad246
Author: Markus Stange <mstange.moz@gmail.com>
Date:   Thu,  9 Oct 2025 18:11:57 +0000

Bug 1993383 - Trigger a repaint of the window in the parent process after a GPU process crash. r=bradwerth

Differential Revision: https://phabricator.services.mozilla.com/D268052

Diffstat:
M
widget/cocoa/nsCocoaWindow.h
 | 
2
++
M
widget/cocoa/nsCocoaWindow.mm
 | 
24
++++++++++++++++++++++++

2 files changed, 26 insertions(+), 0 deletions(-)
diff --git a/widget/cocoa/nsCocoaWindow.h b/widget/cocoa/nsCocoaWindow.h
@@ -392,6 +392,8 @@ class nsCocoaWindow final : public nsBaseWidget {
 
   void CreateCompositor(int aWidth, int aHeight) override;
   void DestroyCompositor() override;
+  void NotifyCompositorSessionLost(
+      mozilla::layers::CompositorSession* aSession) override;
   void SetCompositorWidgetDelegate(
       mozilla::widget::CompositorWidgetDelegate*) override;
 
diff --git a/widget/cocoa/nsCocoaWindow.mm b/widget/cocoa/nsCocoaWindow.mm
@@ -974,6 +974,30 @@ void nsCocoaWindow::DestroyCompositor() {
   nsBaseWidget::DestroyCompositor();
 }
 
+void nsCocoaWindow::NotifyCompositorSessionLost(
+    mozilla::layers::CompositorSession* aSession) {
+  // The GPU process has crashed.
+  //
+  // Trigger a repaint of this window.
+  // Without this, WebRender won't receive a display list for this
+  // window until something else triggers a parent-side repaint. So tab
+  // contents would remain frozen until the user moves the mouse over a
+  // UI element, for example.
+  //
+  // The Windows equivalent to this code is InvalidateWindowForDeviceReset.
+  //
+  // We wait for a short time before the repaint in order to avoid
+  // flashing tab content - if we were to trigger the parent-side paint
+  // immediately, the composite would briefly hide the tab contents because
+  // the new compositor won't have a display list for the tab yet.
+  const double kTriggerPaintDelayAfterGpuProcessCrash = 0.4;  // 400ms
+  [mChildView performSelector:@selector(markLayerForDisplay)
+                   withObject:nil
+                   afterDelay:kTriggerPaintDelayAfterGpuProcessCrash];
+
+  nsBaseWidget::NotifyCompositorSessionLost(aSession);
+}
+
 void nsCocoaWindow::SetCompositorWidgetDelegate(
     mozilla::widget::CompositorWidgetDelegate* aDelegate) {
   if (aDelegate) {