title: How to specify which content scripts which will run on all_frames and which won't?
body: <p>When specifying parameters in the manifest file of a chrome extension there is an option <code>all_frames</code>. This allows the content scripts to be embedded in all frames of a page or not.  </p>
  
  <p>An example of what I want to achieve is have a.js running with <strong>all_frames=false</strong> and b.js with <code>all_frames=true</code>. </p>