WebKit does not expose that Picasa is installed
0. Make sure picasa is installed
1. Go to any random picasa album:
2. Notice how in FF/IE between "Share" and "Print" there is a "Download" pop-down which allows you to download the album to your copy of picasa. In Safari there is no such link.
The page seems to be doing this:
var _picasaInstalled = !!(navigator.mimeTypes['application/x-picasa-detect'] ||
<!--[if gte Picasa 2.0]>
_picasaInstalled = true;
One guess is that FF might be including mime types from registry key HKCR\MIME\Database\Content Type and that WebKit is not. Not sure.
It looks like FF will return a MimeType object when queried for 'x-picasa-detect', but if you enumerate navigator.mimeTypes, this value won't appear in the result set.
Picasa has decided to change their behavior in a future version.