On enabling this functionality in my extension, my script is executing multiple times

[AnkitSharma90]

myScript.js :-

xdLocalStorage.init(
{
iframeUrl:'https://rawgit.com/ofirdagan/cross-domain-local-storage/master/app/views/cross-domain-local-storage.html',
initCallback: function () {
console.log('Got iframe ready');
xdLocalStorage.setItem('check', 'no callback');
}
}
);

Manifest :-

"content_scripts":[
{
"matches": ["://.com/*"],
"css": ["css/main.css"],
"js": ["js/background.js","js/jq.js","js/xdLocalStorage.min.js","js/myScript.js"],
"html":["html/popup.html"],
"all_frames": true
}]