Chrome Canary (perhaps, the Dev channel, too) supports navigation to CSS selectors, property names and values (Ctrl-click them) in the corresponding Sass resources (the Sources panel). You can edit Sass and save it to disk (right-click the editor, "Save as...").
Now, if you have the "Support for Sass" experiment enabled, you'll see the "Auto-reload CSS upon Sass save" timeout setting to reload re-generated CSS files after "sass --watch in:out --sourcemap" (or equivalent) has updated them on the local disk.
Now, if you have the "Support for Sass" experiment enabled, you'll see the "Auto-reload CSS upon Sass save" timeout setting to reload re-generated CSS files after "sass --watch in:out --sourcemap" (or equivalent) has updated them on the local disk.