Bookmarks permission for Google Chrome

I currently looking to build a Google Chrome Extension that fetches bookmarks from the the browser and sent them to server from synchronization perspective,but it seem to always complain me of "permission error" for the "API method" used in "background.html", even though I have set the necessary permission in "manifest.json"

Here what my manifest.json look like

{
  "name" : "Sync BookMark",
  "background_page": "background.html",
  "version" : "1.0",
  "content_script" : {
    "css"       : ["bookmark.css"],
    "js"        : ["js/jquery.js","js/bookmark.js"]

  },
  "browser_action" 开发者_开发百科 :  {
    "default_icon"  :  "images/bookmark.png",    
    "default_title" :  "Syn Bookmark",
    "default_popup" :  "bookmark.html"
  },  
  "permission" : [ 
    "bookmarks",
    "management",
    "unlimitedStorage"

  ]
}  

And Here my background.html code

chrome.bookmarks.getTree(function(bookmarks) {
  printBookmarks(bookmarks);
});

function printBookmarks(bookmarks) {
  bookmarks.forEach(function(bookmark) {
    console.debug(bookmark.id + ' - ' + bookmark.title + ' - ' + bookmark.url);
    if (bookmark.children)
      printBookmark(bookmark.children);
  });
}

// The above code is used from the following link

Now if try to debug the above code in the Chrome developer console It return a error of permission of the API methods used.

Got it I just miss an 's' in permission i.e "permission" instead of "permissions"