Create flags in options to conditionally enable multi frame support

gulpfile.js

@@ -326,6 +326,7 @@ gulp.task('serve-live-reload', ['serve-package'], function () {
   var LiveReloadServer = require('./scripts/gulp/live-reload-server');
   liveReloadServer = new LiveReloadServer(3000, {
     clientUrl: `http://${packageServerHostname()}:3001/hypothesis`,
+    enableMultiFrameSupport: !!process.env.MULTI_FRAME_SUPPORT,
   });
 });
 

src/annotator/guest.coffee

@@ -81,6 +81,8 @@ module.exports = class Guest extends Delegator
     this.anchors = []
 
     cfOptions =
+      enableMultiFrameSupport: config.enableMultiFrameSupport
+      embedScriptUrl: config.embedScriptUrl
       on: (event, handler) =>
         this.subscribe(event, handler)
       emit: (event, args...) =>