- 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
int bits = 0;
  for (const T& item : vec)
    bits |= item;
  return bits;
}
}  
namespace mate {
template<>
struct Converter<base::char16> {
  static bool FromV8(v8::Isolate* isolate, v8::Handle<v8::Value> val,
                     base::char16* out) {
    base::string16 code = base::UTF8ToUTF16(V8ToString(val));
    if (code.length() != 1)
      return false;
    *out = code[0];
    return true;
  }
};
template<>
struct Converter<blink::WebInputEvent::Type> {
  static bool FromV8(v8::Isolate* isolate, v8::Handle<v8::Value> val,