{
    "manifest_version": 2,

    "name": "tabs",
    "description": "testing tabs",
    "version": "1.0.4",
    "icons": { "128": "icon_128.png" },
    "browser_action": {
      "default_icon": "icon.png",
      "default_title": "A popup will come here"
    },
    "background": {
      "scripts": ["background.js"]
    },
     "permissions": ["tabs", "*://*/*", "background"]
  }

chrome.tabs.query({}, function(tabs) {
        for(var i= 0; i < tabs.length; i++) {
            chrome.tabs.executeScript(null, {
            code: "console.log('wow');"
        });
    }

});