From 6f4ed8f62d8e55564f430808146c70b231e74cc1 Mon Sep 17 00:00:00 2001
From: Raymond Zhao <7199958+rzhao271@users.noreply.github.com>
Date: Fri, 2 Sep 2022 15:38:56 -0700
Subject: [PATCH 1/2] fix: Set background for WCO container

---
 shell/browser/ui/views/win_caption_button_container.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/shell/browser/ui/views/win_caption_button_container.cc b/shell/browser/ui/views/win_caption_button_container.cc
index 62ce6d9e5b880..92c0fca690cbd 100644
--- a/shell/browser/ui/views/win_caption_button_container.cc
+++ b/shell/browser/ui/views/win_caption_button_container.cc
@@ -14,6 +14,7 @@
 #include "shell/browser/ui/views/win_frame_view.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/strings/grit/ui_strings.h"
+#include "ui/views/background.h"
 #include "ui/views/layout/flex_layout.h"
 #include "ui/views/view_class_properties.h"
 
@@ -128,6 +129,8 @@ void WinCaptionButtonContainer::AddedToWidget() {
   UpdateButtons();
 
   if (frame_view_->window()->IsWindowControlsOverlayEnabled()) {
+    SetBackground(views::CreateSolidBackground(
+        frame_view_->window()->overlay_button_color()));
     SetPaintToLayer();
   }
 }

From e2c81d0cbf4c343efdc8f2d3522c7eb4bbe41547 Mon Sep 17 00:00:00 2001
From: Raymond Zhao <7199958+rzhao271@users.noreply.github.com>
Date: Tue, 6 Sep 2022 11:13:23 -0700
Subject: [PATCH 2/2] Add background when invalidating as well

---
 shell/browser/ui/views/win_frame_view.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/shell/browser/ui/views/win_frame_view.cc b/shell/browser/ui/views/win_frame_view.cc
index cea0b2937c92a..ad01b0cbac91e 100644
--- a/shell/browser/ui/views/win_frame_view.cc
+++ b/shell/browser/ui/views/win_frame_view.cc
@@ -19,6 +19,7 @@
 #include "ui/display/win/dpi.h"
 #include "ui/display/win/screen_win.h"
 #include "ui/gfx/geometry/dip_util.h"
+#include "ui/views/background.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/win/hwnd_util.h"
 
@@ -58,6 +59,8 @@ void WinFrameView::InvalidateCaptionButtons() {
   if (!caption_button_container_)
     return;
 
+  caption_button_container_->SetBackground(
+      views::CreateSolidBackground(window()->overlay_button_color()));
   caption_button_container_->InvalidateLayout();
   caption_button_container_->SchedulePaint();
 }