Changing input format does not change the data sent to XSS callback

Installation:
- drupal-7.54 (minimal)
- ckeditor-7.x-1.x-dev
- ckeditor library 4.5.4
- (I also use coffee and admin_menu)

Configure:
- Created Full HTML with no settings
- Created Filtered HTML with Limit HTML tags (default tags)
- Order Filtered HTML above Full HTML in the Text formats list
- Basic content type with only a body field

Steps to reproduce:
- Visit node/add of the content type
- See that Filtered HTML is the active text format
- Change text format to Full HTML
- Switch to plain text editor
- Paste iframe (eg. youtube embed code)
- Switch to rich text editor
- See the XHR request to ckeditor/xss contain "input_format: filtered_html" (should be full_html)