### Preflight Checklist

- [X] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
- [X] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md) that this project adheres to.
- [X] I have searched the [issue tracker](https://www.github.com/electron/electron/issues) for a feature request that matches the one I want to file, without success.

### Electron Version

v14.0.0-nightly.20210426

### What operating system are you using?

Windows

### Operating System Version

Windows 10

### What arch are you using?

x64

### Last Known Working Electron version

v14.0.0-nightly.20210413

### Expected Behavior

`BrowserViews` load their `webContents`

### Actual Behavior

BrowserViews will not load `webContents` properly.

### Testcase Gist URL

https://gist.github.com/712a2fde2757736c9dbf6c3e7e0aa18b

### Additional Information

Bisected range: https://github.com/electron/electron/compare/v14.0.0-nightly.20210413...v14.0.0-nightly.20210426
shell/browser/native_browser_view_views.cc
const gfx::Size& window_size) {
  if ((auto_resize_flags_ & AutoResizeFlags::kAutoResizeHorizontal) &&
      !auto_horizontal_proportion_set_) {
    auto* iwc_view = GetInspectableWebContentsView();
    if (!iwc_view)
      return;
    auto* view = iwc_view->GetView();
    auto view_bounds = view->bounds();
    auto_horizontal_proportion_width_ =
        static_cast<float>(window_size.width()) /
        static_cast<float>(view_bounds.width());
    auto_horizontal_proportion_left_ = static_cast<float>(window_size.width()) /
                                       static_cast<float>(view_bounds.x());
    auto_horizontal_proportion_set_ = true;
  }