### 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

13.1.6

### What operating system are you using?

Ubuntu

### Operating System Version

Ubuntu 21.04

### What arch are you using?

x64

### Last Known Working Electron version

None. Electron 10, 11, 12, 14 are all affected, too.

### Expected Behavior

Nothing should happen

### Actual Behavior

1. Have a page with a webview with a link which includes a `#` (e.g. `<a href="#">Test link</a>`)
2. Zoom the page in via `webContents.setZoomFactor(1.1)`
3. Reset the zoom via `webContents.setZoomFactor(1.0)`
4. Click the link

The page itself stays normal while the webview gets all the way zoomed in and its `zoomFactor` is set to `NaN`.

### Testcase Gist URL

https://gist.github.com/ffflorian/2c60315bfafed606723887a7b2f21010

### Additional Information

![image](https://user-images.githubusercontent.com/5497598/125257302-93d8e300-e2fd-11eb-9a1a-a0a9fbdca258.png)
shell/browser/web_view_guest_delegate.cc
#include "shell/browser/web_view_guest_delegate.h"
#include <memory>
#include "content/browser/web_contents/web_contents_impl.h"  
#include "content/public/browser/navigation_handle.h"
#include "content/public/browser/render_frame_host.h"
#include "content/public/browser/render_process_host.h"
#include "content/public/browser/render_view_host.h"
#include "content/public/browser/render_widget_host.h"
#include "content/public/browser/render_widget_host_view.h"
#include "shell/browser/api/electron_api_web_contents.h"
#include "third_party/blink/public/common/page/page_zoom.h"
namespace electron {
WebViewGuestDelegate::WebViewGuestDelegate(content::WebContents* embedder,
                                           api::WebContents* api_web_contents)
    : embedder_web_contents_(embedder), api_web_contents_(api_web_contents) {}
WebViewGuestDelegate::~WebViewGuestDelegate() {
  ResetZoomController();
}
void WebViewGuestDelegate::AttachToIframe(