Make it possible to subclass MediaQueryListListener

Make it possible to subclass MediaQueryListListener

...so that C++ code can listen to media query changes.

I can't think of a way to test this directly, so this
will be tested via https://codereview.chromium.org/287163010/ when that lands.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=177343

[esprehn, 2014-07-01 19:30:45]

Hmm, this doesn't seem like the right way to do this since now you have a
ScriptState* that's not useful. I think you need to add a subclass for script
ones if you want to go this route.

[cbiesinger, 2014-07-01 19:36:34]

On 2014/07/01 19:30:45, esprehn wrote:
> Hmm, this doesn't seem like the right way to do this since now you have a
> ScriptState* that's not useful. I think you need to add a subclass for script
> ones if you want to go this route.

I liked this approach for two reasons:
- Much simpler equality implementation because I don't need to worry about
subclasses (can't use pointer equality for the JS implementation)
- This is temporary because the JS listener will become an event, at which point
all the JS stuff will be removed from this file

If this does not convince you, I will rework this to use a subclass for script.
Let me know.

[esprehn, 2014-07-01 19:37:51]

On 2014/07/01 at 19:36:34, cbiesinger wrote:
> On 2014/07/01 19:30:45, esprehn wrote:
> > Hmm, this doesn't seem like the right way to do this since now you have a
> > ScriptState* that's not useful. I think you need to add a subclass for
script
> > ones if you want to go this route.
> 
> I liked this approach for two reasons:
> - Much simpler equality implementation because I don't need to worry about
subclasses (can't use pointer equality for the JS implementation)
> - This is temporary because the JS listener will become an event, at which
point all the JS stuff will be removed from this file
> 
> If this does not convince you, I will rework this to use a subclass for
script. Let me know.

Are you going to switch it to an event? How long is temporary?

[esprehn, 2014-07-01 19:48:24]

lgtm then, but please add a FIXME too.

[cbiesinger, 2014-07-01 22:18:01]

On 2014/07/01 19:48:24, esprehn wrote:
> lgtm then, but please add a FIXME too.

Apparently my email response did not make it into the code review-

I will change to an event as soon as I'm done with making <source> listen to
media query changes. Given the upcoming holiday, probably next week.

I've already added a FIXME in the .h.

[cbiesinger, 2014-07-01 22:18:05]

The CQ bit was checked by cbiesinger@chromium.org

[commit-bot: I haz the power, 2014-07-01 22:19:06]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/cbiesinger@chromium.org/361003004/1

[commit-bot: I haz the power, 2014-07-02 00:02:00]

Change committed as 177343