### Issue Details

* **Electron Version:**
  * `8.3.3`
* **Operating System:**
  * Windows 10 2004
* **Last Known Working Electron version:**
  * `7.x`

### Expected Behavior
You can write and read from clipboard via `Buffer`.

### Actual Behavior
You can write but not read.

### To Reproduce

```js
setTimeout(() => {
  clipboard.writeBuffer('code/file-list', Buffer.from("Hello World"));
  console.log("did write")
}, 1000);

setTimeout(() => {
  const res = clipboard.readBuffer('code/file-list');
  console.log(res.toString());
}, 2000);
```

The output is empty with Electron 8 but filled with Electron 7.

//cc @deepak1556 
shell/common/api/electron_api_clipboard.cc
#include "shell/common/api/electron_api_clipboard.h"
#include "base/strings/utf_string_conversions.h"
#include "shell/common/gin_converters/image_converter.h"
#include "shell/common/gin_helper/dictionary.h"
#include "shell/common/node_includes.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "third_party/skia/include/core/SkImageInfo.h"
#include "third_party/skia/include/core/SkPixmap.h"
#include "ui/base/clipboard/clipboard_format_type.h"
#include "ui/base/clipboard/scoped_clipboard_writer.h"
namespace electron {
namespace api {
ui::ClipboardBuffer Clipboard::GetClipboardBuffer(gin_helper::Arguments* args) {