manifest.json

 {
    "name": "TabManager",
    "description" : "Base Level Extension",
    "version": "1.0",
    "manifest_version": 2,
    "browser_action": {
      "default_popup": "TabManager.html",
      "default_icon": "icon.png"
    },
	
	"permissions": [
        "activeTab",
		"tabs"
    ],
	
    "commands": {
      "_execute_browser_action": {
        "suggested_key": {
          "default": "Ctrl+Shift+F",
          "mac": "MacCtrl+Shift+F"
        },
        "description": "Opens hello.html"
      }
    }
	

  
  }