The package in trusty-proposed doesn't solve the problem as described by Daniel Serpell in comment #4. After assigning the audio raise volume button as a shortcut in unity-control-center, the dconf key is set to 'AudioRaiseVolume' rather than 'XF86AudioRaiseVolume'.
$ apt list unity
Listing... Done
unity/trusty-proposed,now 7.2.4+14.04.20141217-0ubuntu1 amd64 [installed,automatic]
$ gsettings get org.gnome.settings-daemon.plugins.media-keys volume-up
'AudioRaiseVolume'
$ gsettings reset org.gnome.settings-daemon.plugins.media-keys volume-up
$ gsettings get org.gnome.settings-daemon.plugins.media-keys volume-up
'XF86AudioRaiseVolume'
The package in trusty-proposed doesn't solve the problem as described by Daniel Serpell in comment #4. After assigning the audio raise volume button as a shortcut in unity-control- center, the dconf key is set to 'AudioRaiseVolume' rather than 'XF86AudioRaise Volume' .
$ apt list unity proposed, now 7.2.4+14. 04.20141217- 0ubuntu1 amd64 [installed, automatic] settings- daemon. plugins. media-keys volume-up settings- daemon. plugins. media-keys volume-up settings- daemon. plugins. media-keys volume-up Volume'
Listing... Done
unity/trusty-
$ gsettings get org.gnome.
'AudioRaiseVolume'
$ gsettings reset org.gnome.
$ gsettings get org.gnome.
'XF86AudioRaise