Usage of nsICommandLine Interface

 Extract the width and height specified on the command line, if present.
 @return A feature string with a prepended comma, e.g. ",width=500,height=400"

AUTF8String getFeatures(in nsICommandLine aCmdLine)

 Process a command line. If this handler finds arguments that it
 understands, it should perform the appropriate actions (such as opening
 a window), and remove the arguments from the command-line array.

 @throw NS_ERROR_ABORT to immediately cease command-line handling
        (if this is STATE_INITIAL_LAUNCH, quits the app).
        All other exceptions are silently ignored.

void handle(in nsICommandLine aCommandLine)

 Process the command-line validators in the proper order, calling
 "validate()" on each.

 @throws NS_ERROR_ABORT if any validator throws NS_ERROR_ABORT. All other
         errors thrown by validators will be silently ignored.

void validate(in nsICommandLine aCommandLine)