title: Chrome extension content script re-injection after upgrade or install
body: <p>After the Chrome extension I'm working on is installed, or upgraded, the content scripts (specified in the manifest) are not re-injected so a page refresh is required to make the extension work. Is there a way to force the scripts to be injected again?</p>
  
  <p>I believe I could inject them again programmatically by removing them from the manifest and then handling which pages to inject in the background page, but this is not a good solution.</p>
  
  <p>I don't want to automatically refresh the user's tabs because that could lose some of their data. Safari automatically refreshes all pages when you install or upgrade an extension.</p>