title: How to run chrome.tabs.insertCSS from the background page on each page?
body: <p>I'd like to add a custom style sheet in a page <em>without</em> a content script. My CSS is OK, but the code below, using the <code>onUpdated</code> and <code>onCreated</code> event listeners do not work.</p>
  
  <p>Part of <code>manifest.json</code>:</p>
  
  <pre><code>"permissions": [
        "http://www.site_domain.com/*",
        "tabs"],
  </code></pre>
  
  <p>background.html<code>:
  </code></p>
  
  <pre><code>chrome.tabs.onUpdated.addListener(function (tab) {
      var tabUrl = tab.url;
      if (tabUrl.indexOf("site_domain") != -1) {
          changeBgkColor();
      }
  });
  
  chrome.tabs.onCreated.addListener(function (tab) {
      var tabUrl = tab.url;
      if (tabUrl.indexOf("site_domain") != -1) {
          changeBgkColor();
      }
  });
  
  function changeBgkColor(){
      chrome.tabs.insertCSS(null, {file:"css/styles.css"})
  };
  </code></pre>