chrome: DCHECK failure in SimpleMenuModel::AddSeparator with --filter-chrome-commands

[magreenblatt]

Describe the bug

1. Run cefclient.exe --enable-chrome-runtime --filter-chrome-commands using a Debug build.
2. Click the 3-dot menu button in the Chrome toolbar

Expected behavior
The application should not crash. Instead, it crashes with the below error and stack trace:

[5600:22356:1004/195900.974:FATAL:simple_menu_model.cc(168)] Check failed: NORMAL_SEPARATOR == separator_type (0 vs. 3)

 	base.dll!logging::CheckError::~CheckError() Line 267	C++
 	ui_base.dll!ui::SimpleMenuModel::AddSeparator(ui::MenuSeparatorType separator_type) Line 169	C++
 	libcef.dll!AppMenuModel::Build() Line 1634	C++
 	libcef.dll!AppMenuModel::Init() Line 865	C++
 	libcef.dll!AppMenuButton::RunMenu(std::__Cr::unique_ptr<AppMenuModel,std::__Cr::default_delete<AppMenuModel>> menu_model, Browser * browser, int run_flags) Line 65	C++
 	libcef.dll!BrowserAppMenuButton::ShowMenu(int run_types) Line 111	C++
 	libcef.dll!BrowserAppMenuButton::ButtonPressed(const ui::Event & event) Line 310	C++

Versions (please complete the following information):

• OS: Windows 10
• CEF Version: M117+

Additional context
Likely related to the changes in this Chromium commit.

Check last visible menu item instead of last one when adding separators

In this case we're adding a new LOWER_SEPARATOR (as separator_type). The previous logic would check the last item in the menu, which is TYPE_SUBMENU. The new logic excludes non-visible items, so it finds a TYPE_SEPARATOR (at index 3 out of 9). The DCHECK then fails because it thinks it's adding a LOWER_SEPARATOR after a NORMAL_SEPARATOR.