[Mac] Edit the profile name and avatar directly in the avatar bubble.

Clicking on the profile name will display a textfield, and hovering over the 
profile photo will display a custom button, which when clicked, will navigate
to the chrome://settings profile editing page.

The implementations is inspired from the views one in /chrome/browser/ui/views/profile_chooser_view.cc

Screenshots: https://docs.google.com/drawings/d/13gmNorwo9QbsZLi2UXMh7M2wkvcrvsIUuneUywuAhf0/edit?usp=sharing

BUG=324036

Review URL: https://codereview.chromium.org/146143002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247368 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 247368