1. Documentation. Make it clear what is the size of the image should be
   specified in function chrome.devtools.panels.create(). On the basis of
   my own observations, it's 32x32 when DevTools is undocked, however 24x24
   when docked. Here is an old issue<http://code.google.com/p/chromium/issues/detail?id=124791>related to this.
   2. Manifest file. Why we had to use "devtools_page" directive instead of
   specifying scripts, just like we prefer "background" directive to
   "background_page" in manifest version 2?