- Electron version: 1.2.0
- Operating system: Mac OS X - 10.11.5

I upgraded from 1.1.1 to 1.2.0. 1.2.0 breaks on the following `index.html`:

``` html
<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8">
        <script>
            console.log(process.env.NODE_ENV)
        </script>
    </head>
    <body>
        <div id="app-container"></div>
    </body>
</html>
```

Error:

```
Uncaught ReferenceError: process is not defined
```

atom/renderer/atom_renderer_client.cc
}
void AtomRendererClient::RenderThreadStarted() {
  blink::WebCustomElement::addEmbedderCustomElementName("webview");
  blink::WebCustomElement::addEmbedderCustomElementName("browserplugin");
  OverrideNodeArrayBuffer();
  preferences_manager_.reset(new PreferencesManager);
#if defined(OS_WIN)
  
  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
  base::string16 app_id =
      command_line->GetSwitchValueNative(switches::kAppUserModelId);
  if (!app_id.empty()) {
    SetCurrentProcessExplicitAppUserModelID(app_id.c_str());
  }
#endif
#if defined(OS_MACOSX)
  
  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
  if (!command_line->HasSwitch(switches::kScrollBounce)) {
    base::ScopedCFTypeRef<CFStringRef> key(
        base::SysUTF8ToCFStringRef("NSScrollViewRubberbanding"));
    base::ScopedCFTypeRef<CFStringRef> value(
        base::SysUTF8ToCFStringRef("false"));
    CFPreferencesSetAppValue(key, value, kCFPreferencesCurrentApplication);
    CFPreferencesAppSynchronize(kCFPreferencesCurrentApplication);
  }
#endif
}
void AtomRendererClient::RenderFrameCreated(