Remove the mode getter/setter for in-band text tracks

Remove the mode getter/setter for in-band text tracks

TextTrack::setMode() is virtual and overridden by InbandTextTrack to
forward all the way down to Chromium's WebInbandTextTrackImpl, where
it is simply stored. However, the getter is not virtual and does not
ever retrieve the value, so all of this is elaborate dead code.

Because InbandTextTrack::setMode() first called TextTrack::setMode(),
this assymetry between getting and setting for in-band tracks didn't
actually break anything, and the relevant tests still pass.

In addition, in-band tracks should not need to know about the mode,
they simply provide cues for Blink, whether or not they are rendered
can be left an internal matter.

The Chromium side can be removed after a Blink roll, after which
WebInbandTextTrack::Mode can finally be removed as well.

BUG=315476
TEST=LayoutTests/media/track/opera/interfaces/TextTrack/mode.html

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=161456

[philipj_slow, 2013-11-06 08:28:10]

Jochen, can you take this, since it touches public/web?

[jochen (gone - plz use gerrit), 2013-11-06 10:58:34]

is it possible to add a test for this? At least to make sure that setMode/mode
work as expected?

[philipj_slow, 2013-11-06 11:37:13]

On 2013/11/06 10:58:34, jochen wrote:
> is it possible to add a test for this? At least to make sure that setMode/mode
> work as expected?

The test coverage for this is already high, when I intentionally break
TextTrack::mode() or setMode(), lots of tests in media/track start failing,
including media/track/opera/interfaces/TextTrack/mode.html

[jochen (gone - plz use gerrit), 2013-11-06 11:49:22]

but there was nothing that checked that if you set the mode, you can also read
it back?

[jochen (gone - plz use gerrit), 2013-11-06 11:49:22]

but there was nothing that checked that if you set the mode, you can also read
it back?

[philipj_slow, 2013-11-06 11:58:32]

On 2013/11/06 11:49:22, jochen wrote:
> but there was nothing that checked that if you set the mode, you can also read
> it back?

There is, if I break only TextTrack::mode() to always return "subtitles",
media/track/opera/interfaces/TextTrack/mode.html will fail.

[jochen (gone - plz use gerrit), 2013-11-06 12:03:36]

lgtm

[commit-bot: I haz the power, 2013-11-06 12:05:06]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/philipj@opera.com/60203008/1

[commit-bot: I haz the power, 2013-11-06 13:50:27]

Retried try job too often on win_blink_rel for step(s) webkit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_blink_...

[commit-bot: I haz the power, 2013-11-06 13:52:26]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/philipj@opera.com/60203008/1

[commit-bot: I haz the power, 2013-11-06 14:30:09]

Change committed as 161456