title: Auto paste clipboard on load page @ chrome extension
body: <p>I'm creating a website that the main issue in it is pasting stuff from clipboard, and an extension for that.</p>
  
  <p>I want to auto-paste clipboard content when a specific page is opened.</p>
  
  <p>For some reason the execCommand("Paste") is not executed when the page is loaded.</p>
  
  <p><strong>content.js</strong></p>
  
  <pre><code>setTimeout(function() { chrome.extension.sendMessage({greeting: "hello"},function(response){}); },200);
  </code></pre>
  
  <p><strong>background.js</strong></p>
  
  <pre><code>chrome.extension.onMessage.addListener(
    function(request, sender, sendResponse) {
  document.execCommand("Paste");
    sendResponse({});
    return true;
  });
  </code></pre>
  
  <p><strong>manifest.json</strong></p>
  
  <pre><code>"background": {
    "page": "src/bg/background.html",
    "persistent": true
  },
  "options_page": "src/options/index.html",
  "permissions": [
    "clipboardRead",
    "clipboardWrite",
    "fileBrowserHandler",
    "*my website address*"
  ],
  "content_scripts": [
  {
  "matches": [
          "*my website address*"
      ],
  "js": ["js/content.js"],
      "run_at": "document_end"
  }
  ]
  </code></pre>
  
  <p>everything works great until the paste is needed to be done and it's just not working...</p>
  
  <p>thanks :)</p>