Allow a View to specify a non-default native theme (i.e. different from

ui/views/view.cc

Index: ui/views/view.cc
diff --git a/ui/views/view.cc b/ui/views/view.cc
index 7345e71a3ec6e14d61efad8e537f6efe64b9b80e..2a5e74ea8c216cc18a82a0d7472c82734f191bd4 100644
--- a/ui/views/view.cc
+++ b/ui/views/view.cc
@@ -924,6 +924,12 @@ const ui::ThemeProvider* View::GetThemeProvider() const {
 }
 
 const ui::NativeTheme* View::GetNativeTheme() const {
+  if (native_theme_override_)
+    return native_theme_override_;
+
+  if (parent())
+    return parent()->GetNativeTheme();
+
   const Widget* widget = GetWidget();
   if (widget)
     return widget->GetNativeTheme();
@@ -931,6 +937,13 @@ const ui::NativeTheme* View::GetNativeTheme() const {
   return ui::NativeTheme::GetInstanceForNativeUi();
 }
 
+void View::SetNativeThemeOverride(ui::NativeTheme* theme) {
+  ui::NativeTheme* original_native_theme = GetNativeTheme();
+  native_theme_override_ = theme;
+  if (native_theme_override_ != original_native_theme)
+    PropagateNativeThemeChanged(theme);
+}
+
 // RTL painting ----------------------------------------------------------------
 
 void View::EnableCanvasFlippingForRTLUI(bool enable) {
@@ -1975,6 +1988,9 @@ void View::ViewHierarchyChangedImpl(
 }
 
 void View::PropagateNativeThemeChanged(const ui::NativeTheme* theme) {
+  if (native_theme_override_ && native_theme_override_ != theme)
+    return;
+
   {
     internal::ScopedChildrenLock lock(this);
     for (auto* child : children_)