- Electron version: 1.4.0
- Operating system: OS X 10.10.5

I've been using the following code to send Tab key events to a webview in my project:

``` js
const webContents = webView.getWebContents();
const keyEvent = {
  type: 'keyDown',
  keyCode: 'Tab'
};

webContents.sendInputEvent(keyEvent);
```

I have had no issues with this until the recent update to 1.4.0.

The last version the above code works in OS X is **1.3.7**. I've tried this with the latest versions of Electron (1.4.1 & 1.4.2) with the same results.

Am I doing something wrong here? Is this a known issue?

atom/common/native_mate_converters/blink_converter.cc
v8::Isolate* isolate, const blink::WebContextMenuData::MediaType& in) {
  switch (in) {
    case blink::WebContextMenuData::MediaTypeImage:
      return mate::StringToV8(isolate, "image");
    case blink::WebContextMenuData::MediaTypeVideo:
      return mate::StringToV8(isolate, "video");
    case blink::WebContextMenuData::MediaTypeAudio:
      return mate::StringToV8(isolate, "audio");
    case blink::WebContextMenuData::MediaTypeCanvas:
      return mate::StringToV8(isolate, "canvas");
    case blink::WebContextMenuData::MediaTypeFile:
      return mate::StringToV8(isolate, "file");
    case blink::WebContextMenuData::MediaTypePlugin:
      return mate::StringToV8(isolate, "plugin");
    default:
      return mate::StringToV8(isolate, "none");
  }
}
v8::Local<v8::Value> Converter<blink::WebContextMenuData::InputFieldType>::ToV8(