root/chrome/browser/extensions/api/extension_action/

[..]
  1. browser_action_apitest.cc
  2. browser_action_browsertest.cc
  3. browser_action_interactive_test.cc
  4. extension_action_api.cc
  5. extension_action_api.h
  6. extension_action_prefs_unittest.cc
  7. extension_page_actions_api_constants.cc
  8. extension_page_actions_api_constants.h
  9. page_action_apitest.cc
[..]