Remove mail blockquote special case handling.

Remove mail blockquote special case handling.

Throughout the editing code, we have special handling for Mail.app's
blockquotes (a blockquote with type=cite). We no longer support
Mail.app, and adding this attribute results in unique, undocumented
editing behavior that's web facing but with no path (nor interest)
towards standardization.

Mozilla also handles blockquote type=cite differently (they're trying to
get rid of it https://bugzilla.mozilla.org/show_bug.cgi?id=183219),
though it affects style only, not editing behavior. Our normal editing
behavior without this special handling matches Mozilla's more closely.

I've checked and there's no reliance on this special behavior in any
of Google's rich text editing code, and I couldn't find any usage or
info about this behavior on the broader internet.

[eseidel, 2013-04-09 23:50:31]

Ojan is your guy here.

[leviw_travelin_and_unemployed, 2013-04-10 17:33:34]

I added more info to the description.

Ojan - I'm happy to use a feature observer to watch for this for awhile if you
think that's a better idea.

[ojan, 2013-04-16 21:44:30]

Sorry this took me so long to get back to you on. I've tested a bunch of stuff
and I agree that the delete/paste behavior here is crazypants, buggy and we
should get rid of it.

On the other hand, I think the InsertNewlineInQuotedContent behavior is awesome
and we should eventually try to standardize it. Also, it's exposed to the web,
so we should FeatureObserver it before trying to remove it. If we just keep the
execCommand and get rid of the crazypants delete/paste behavior though, I think
keeping this feature incurs very little cost on the codebase since the logic is
all contained to BreakBlockquoteCommand.

Sound good?

On a side note, it'd be great if we could FeatureObserver all the execCommands
and see which ones we can kill. Some of them are crazypants.

https://codereview.chromium.org/13954003/diff/1/LayoutTests/editing/execComma...
File LayoutTests/editing/execCommand/enabling-and-selection.html (left):

https://codereview.chromium.org/13954003/diff/1/LayoutTests/editing/execComma...
LayoutTests/editing/execCommand/enabling-and-selection.html:9: <script
src="script-tests/enabling-and-selection.js"></script>
You should also delete the js file in the script-tests directory. I didn't look
closely, but there are probably other script-tests in this patch.

[eseidel, 2013-04-27 08:56:49]

should this be closed?