* Electron Version: 3.0.0-beta.3
* Operating System Ubuntu 18.04
* Last known working Electron version: none  ... still fails on 2.0.5

**Expected Behavior**

Font Subpixel AA should work... only works when rendering a .HTML file, not via BrowserWindow.

**Actual behavior**

Subpixel AA only works when I load a .html file.. not a .js file.

**To Reproduce**

https://github.com/burtonator/electron3-fuzzy-text

Here is a repo.

This works:

```
./node_modules/.bin/electron test.html
```

This will fail:

```
./node_modules/.bin/electron index.js
```
The only way to actually see that it's failing is to use a zoom tool like ```kmag```

**Screenshots**

Here's loading the .html file on the command line. Notice the AA is working by the orange color on the outside of the text:

![image](https://user-images.githubusercontent.com/45447/43037663-8731acd2-8cc4-11e8-99bf-f2adfbfdecc4.png)

Here is the SAME text and same test.html file but I loaded it via BrowserWindow in my index.js script.

![image](https://user-images.githubusercontent.com/45447/43037676-a22fa30e-8cc4-11e8-8bee-4d20bdfde57f.png)

Electron fails to use AA text rendering in the new window.  

Hopefully this might help track down the bug.  


atom/browser/web_contents_preferences.cc
content::WebPreferences* prefs) {
  prefs->javascript_enabled = IsEnabled("javascript", true );
  prefs->images_enabled = IsEnabled("images", true );
  prefs->text_areas_are_resizable =
      IsEnabled("textAreasAreResizable", true );
  prefs->navigate_on_drag_drop =
      IsEnabled("navigateOnDragDrop", false );
  
  bool is_webgl_enabled = IsEnabled("webgl", true );
  prefs->webgl1_enabled = is_webgl_enabled;
  prefs->webgl2_enabled = is_webgl_enabled;
  
  bool is_web_security_enabled =
      IsEnabled(options::kWebSecurity, true );
  prefs->web_security_enabled = is_web_security_enabled;
  prefs->allow_running_insecure_content =
      IsEnabled(options::kAllowRunningInsecureContent,
                !is_web_security_enabled );