### 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/api/electron_api_browser_window.cc
content::RenderViewHost* new_host) {
  if (old_host)
    old_host->GetWidget()->RemoveInputEventObserver(this);
  if (new_host)
    new_host->GetWidget()->AddInputEventObserver(this);
}
void BrowserWindow::RenderFrameCreated(
    content::RenderFrameHost* render_frame_host) {
  if (!window()->transparent())
    return;
  content::RenderWidgetHostImpl* impl = content::RenderWidgetHostImpl::FromID(
      render_frame_host->GetProcess()->GetID(),
      render_frame_host->GetRoutingID());
  if (impl)
    impl->owner_delegate()->SetBackgroundOpaque(false);
}
void BrowserWindow::DidFirstVisuallyNonEmptyPaint() {
  if (window()->IsVisible())
    return;
  
  
  auto* const view = web_contents()->GetRenderWidgetHostView();
  view->Show();
  view->SetSize(window()->GetContentSize());
}
void BrowserWindow::BeforeUnloadDialogCancelled() {