Fix a crash due to reentrancy in the widget while processing a theme changed notification after com…

ui/views/widget/widget.cc

Index: ui/views/widget/widget.cc
diff --git a/ui/views/widget/widget.cc b/ui/views/widget/widget.cc
index 6063a224684cb38ec980a29621197060167065c1..7e9fdb64bb125b795fab8b11f00478828d40a9cd 100644
--- a/ui/views/widget/widget.cc
+++ b/ui/views/widget/widget.cc
@@ -4,6 +4,7 @@
 
 #include "ui/views/widget/widget.h"
 
+#include "base/auto_reset.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
@@ -174,7 +175,8 @@ Widget::Widget()
       auto_release_capture_(true),
       views_with_layers_dirty_(false),
       movement_disabled_(false),
-      observer_manager_(this) {}
+      observer_manager_(this),
+      processing_theme_changed_(false) {}
 
 Widget::~Widget() {
   DestroyRootView();
@@ -898,6 +900,8 @@ void Widget::DebugToggleFrameType() {
 }
 
 void Widget::FrameTypeChanged() {
+  if (processing_theme_changed_)
+    return;
   native_widget_->FrameTypeChanged();
 }
 
@@ -1401,6 +1405,10 @@ void Widget::OnNativeThemeUpdated(ui::NativeTheme* observed_theme) {
     observer_manager_.Add(current_native_theme);
   }
 
+  DCHECK_EQ(processing_theme_changed_, false);
+
+  base::AutoReset<bool> auto_theme_changed_recursion_break(
+      &processing_theme_changed_, true);
   root_view_->PropagateNativeThemeChanged(current_native_theme);
 }