Examine source code of Speak Selection

{
  "name": "Speak Selection",
  "version": "1.1",
  "description": "Speaks the current selection out loud.",
  "permissions": [
    "<all_urls>",
    "tts",
    "tabs"
  ],
  "background": {
    "scripts": [
      "keycodes.js",
      "tabs.js",
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": "SpeakSel19.png",
    "default_title": "Speak Selection"
  },
  "options_page": "options.html",
  "minimum_chrome_version": "14",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "all_frames": true,
      "js": [
        "keycodes.js",
        "content_script.js"
      ]
    }
  ],
  "icons": {
    "16": "SpeakSel16.png",
    "48": "SpeakSel48.png",
    "128": "SpeakSel128.png",
    "256": "SpeakSel256.png"
  },
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{84c6f076-ee36-4e26-b4bf-533b9d46eb3a}"
    }
  }
}