@tmpsantos , please check the comments inline below, I paste here again. Hopefully it explain the situation.
```
      // libva drivers won't get loaded even above two libraries get dlopened.
      // Thus, libva calls will fail after post sandbox stage.
      //
      // To get the va driver loadded before sandboxing, upstream simply dlopen
      // the hard-coded va driver path because ChromeOS is the only platform
      // that Google want to support libva.
      //
      // While generic linux distros ship va driver as anywhere they want.
      // Fortunately, the va driver will be loadded when vaInitialize() get
      // called.
      // So the following code is to call vaInitialize() before sandboxing.
```