[webkit-dev] Removing the prefix from webkitPostMessage

[Adam Barth]

On Wed, Sep 12, 2012 at 6:03 PM, Maciej Stachowiak <mjs at apple.com> wrote:
> On Sep 12, 2012, at 5:51 PM, Adam Barth <abarth at webkit.org> wrote:
>> On Wed, Sep 12, 2012 at 5:34 PM, Maciej Stachowiak <mjs at apple.com> wrote:
>>> On Sep 12, 2012, at 5:10 PM, Adam Barth <abarth at webkit.org> wrote:
>>>> I've posted a patch to delete webkitPostMessage in favor of the
>>>> identically behaving, unprefixed postMessage:
>>>>
>>>> https://bugs.webkit.org/show_bug.cgi?id=96577
>>>>
>>>> We've discussed this topic previously in
>>>> <http://lists.webkit.org/pipermail/webkit-dev/2012-April/020237.html>.
>>>> In that thread, I was asked to follow the instructions in
>>>> <https://trac.webkit.org/wiki/DeprecatingFeatures>, but those
>>>> instructions are too hard.
>>>
>>> Really? I thought it was pretty easy for Chrome to gather "usage statistics in the wild (either by instrumenting the browser or any other means)" using what people call the "histogram" mechanism. Is it now a lot harder?
>>
>> My evidence for it being too hard is that no one has actually been
>> able to use that process to delete any prefixes.
>
> I've never seen anyone post usage data for a prefixed feature, nor report trying to do so and failing. Taking the inside view, do you believe gathering the suggested data would be too hard? It would be a better argument for changing the process if someone tried and failed, or tried and reported it being too much effort.
>
> Alternate hypotheses for no one even trying to gather the data: no one has been sufficiently motivated to remove a prefixed feature to do even a modest amount of research. It sounds like you are highly motivated since you believe it is a matter of good faith as a browser engine.
>
> Are you willing to be the guinea pig for the process? A bunch of WebKit hackers (not including me incidentally) proposed it at the last WebKit Contributor's meeting, it would be a shame if we discarded it without anyone even trying it.

I don't think we should adopt policies without some evidence that they
work.  I'm glad that we had a discussion about this topic at the
contributor's meeting, and I'm also glad that we tried out
<https://trac.webkit.org/wiki/DeprecatingFeatures>, but my view is
that the experiment has been a failure because we have not succeeded
in removing any vendor prefixes.

As an alternative, I suggest we experiment with different approaches
to removing vendor prefix, learn what works and what doesn't work, and
then revisit whether we need a policy once we have more experience.

For example, I just sent a message to webkit-dev describing my
experience removing the -khtml- and -apple- prefixes from all CSS
properties.  In that work, we used an ENABLE macro to make it easy to
toggle the prefixes on and off.  I'd be happy to add an ENABLE macro
in https://bugs.webkit.org/show_bug.cgi?id=96577 so that we can start
by deleting the prefix in one port, learn from the experience, and
then decide whether to delete the prefix in the rest of the ports.

Adam