Improve exception messages in Source/core/dom/Attr.h

I guess alphabetically is as good a way as any of working through the
rather larger number of DOM callsites...

BUG=270033

Review URL: https://chromiumcodereview.appspot.com/23567040

git-svn-id: svn://svn.chromium.org/blink/trunk@157898 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Improve exception messages for legacy notifications.

One of these exceptions apparently doesn't work. Hooray. (See also the
checked-in "FAIL" result for 'fast/notifications/notifications-without-permission.html'

BUG=270033
R=jochen@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23460045

git-svn-id: svn://svn.chromium.org/blink/trunk@157899 bbb929c8-8fbe-4397-9dbb-9b2b20218538