Examine source code of Color Coded Ruler

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  "name": "__MSG_extensionName__",
  "version": "1.0",
  "description": "__MSG_extensionDescription__",
  "permissions": [
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icons/icon128.png"
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "web_accessible_resources": [
    "content.css"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{37615142-c82e-4bba-989c-0953ea5b51d3}"
    }
  }
}