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# Description

* Electron version: 1.8.4
* Operating system: Windows 10

Calling `webContents.sendInputEvent` with type as `"char"` to a document containing a webview is rendered offscreen and an input panel is focused

<!-- What do you think should happen? -->

# Expected result

Keyboard input should be placed into the input panel

<!-- What actually happens? -->

# Actual result

Electron crashes

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# Repro steps

[I have a repo set up that will demonstrate the issue.](https://github.com/ImOnALampshade/electron-webview-char-crash) Clone that to see. Read the readme in that for more information.

```bash
git clone https://github.com/ImOnALampshade/electron-webview-char-crash.git
npm install
npm start
```
atom/browser/api/atom_api_web_contents.cc
auto* context = GetServiceWorkerContext(web_contents());
  if (!context)
    return;
  struct WrappedCallback {
    base::Callback<void(bool)> callback_;
    explicit WrappedCallback(const base::Callback<void(bool)>& callback)
        : callback_(callback) {}
    void Run(content::ServiceWorkerCapability capability) {
      callback_.Run(capability !=
                    content::ServiceWorkerCapability::NO_SERVICE_WORKER);
      delete this;
    }
  };
  auto* wrapped_callback = new WrappedCallback(callback);
  context->CheckHasServiceWorker(
      web_contents()->GetLastCommittedURL(), GURL::EmptyGURL(),
      base::BindOnce(&WrappedCallback::Run,
                     base::Unretained(wrapped_callback)));
}
void WebContents::UnregisterServiceWorker(
    const base::Callback<void(bool)>& callback) {
  auto* context = GetServiceWorkerContext(web_contents());
  if (!context)
    return;
  context->UnregisterServiceWorker(web_contents()->GetLastCommittedURL(),
                                   callback);
}
void WebContents::SetIgnoreMenuShortcuts(bool ignore) {