title: Use existing jQuery in Chrome extension content script?
body: <p>Everything I find seems to involve injecting jQuery, but I know jQuery already exists on the page (the browser JS console lets me use it).</p>
  
  <p>I have a background script that is sending a message to my content script, which is running the function. When that function executes I get:</p>
  
  <blockquote>
    <p>Error in event handler for runtime.onMessage: ReferenceError: jQuery
    is not defined</p>
  </blockquote>
  
  <p>(I've tried both $ and jQuery references)</p>
  
  <p>Any ideas why I cannot access the existing jquery object from the content script?</p>