### 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

12.0.5

### What operating system are you using?

Ubuntu

### Operating System Version

Ubuntu 21.04 x86_64 5.11.0-16-generic

### What arch are you using?

x64

### Last Known Working Electron version

_No response_

### Expected Behavior

All clicking inside the developer tool works well and not being interrupted by dragging the electron app.

### Actual Behavior

When I click the `option` and `close` tool inside the developer tool, it drags the electron app.

https://user-images.githubusercontent.com/61906684/118137437-666fd600-b42f-11eb-9443-ea1ebad1d0ec.mp4



### Testcase Gist URL

_No response_

### Additional Information

This bug only occurs if the dock position is on the left.
shell/browser/ui/views/inspectable_web_contents_view_views.cc
if (devtools_window_web_view_)
    return devtools_window_web_view_->HasFocus();
  else if (devtools_web_view_)
    return devtools_web_view_->HasFocus();
  else
    return false;
}
void InspectableWebContentsViewViews::SetIsDocked(bool docked, bool activate) {
  CloseDevTools();
  if (!docked) {
    devtools_window_ = std::make_unique<views::Widget>();
    devtools_window_web_view_ = new views::WebView(nullptr);
    devtools_window_delegate_ = new DevToolsWindowDelegate(
        this, devtools_window_web_view_, devtools_window_.get());
    views::Widget::InitParams params;
    params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
    params.delegate = devtools_window_delegate_;
    params.bounds = inspectable_web_contents()->GetDevToolsBounds();
#if defined(OS_LINUX)
    params.wm_role_name = "devtools";
    if (GetDelegate())
      GetDelegate()->GetDevToolsWindowWMClass(&params.wm_class_name,
                                              &params.wm_class_class);
#endif
    devtools_window_->Init(std::move(params));
    devtools_window_->UpdateWindowIcon();
  }
  ShowDevTools(activate);
}
void InspectableWebContentsViewViews::SetContentsResizingStrategy(