Allow DOMFileReader to be used in Sandboxes
SWAPI 0: Roles, Labels, and Privileges
SWAPI 1: Sandbox API + associate labels with comparts
New sandbox semantics
SWAPI 2: Use IFC policy on postMessage between labeled compartments
Silently fail cross compartment calls
SWAPI 3: LabeledBlob
SWAPI 4: Document-Label header
SWAPI 5: Labeled XHR