<!--  As an open source project with a dedicated but small maintainer team, it can sometimes take a long time for issues to be addressed so please be patient and we will get back to you as soon as we can.
-->

### Preflight Checklist
<!-- Please ensure you've completed the following steps by replacing [ ] with [x]-->

* [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 for an issue that matches the one I want to file, without success.

### Issue Details

* **Electron Version:**
  * 11.0.0-beta.13
  * 10.0.1
* **Operating System:**
  * Windows 10 (2004)

When calling [`navigator.clipboard.read()`](https://developer.mozilla.org/en-US/docs/Web/API/Clipboard/read) in the renderer process, the session's permission handler receives a request for the permission "unknown".

### Expected Behavior
The permission handler should receive a request for "clipboard-read" permission.

### Actual Behavior
The permission handler receives a request for "unknown" permission.

### To Reproduce
Electron Fiddler: https://gist.github.com/5046d997fb4648edd08ad8a2645e84a0

shell/common/gin_converters/content_converter.cc
switch (static_cast<PermissionType>(val)) {
    case PermissionType::POINTER_LOCK:
      return StringToV8(isolate, "pointerLock");
    case PermissionType::FULLSCREEN:
      return StringToV8(isolate, "fullscreen");
    case PermissionType::OPEN_EXTERNAL:
      return StringToV8(isolate, "openExternal");
    case PermissionType::SERIAL:
      return StringToV8(isolate, "serial");
    default:
      return StringToV8(isolate, "unknown");
  }
}
bool Converter<content::StopFindAction>::FromV8(v8::Isolate* isolate,
                                                v8::Local<v8::Value> val,
                                                content::StopFindAction* out) {
  std::string action;
  if (!ConvertFromV8(isolate, val, &action))
    return false;
  if (action == "clearSelection")
    *out = content::STOP_FIND_ACTION_CLEAR_SELECTION;
  else if (action == "keepSelection")
    *out = content::STOP_FIND_ACTION_KEEP_SELECTION;
  else if (action == "activateSelection")
    *out = content::STOP_FIND_ACTION_ACTIVATE_SELECTION;
  else
    return false;
  return true;
}
v8::Local<v8::Value> Converter<content::WebContents*>::ToV8(