Implement seekable() according to the MediaSource specification

Implement seekable() according to the MediaSource specification

BUG=432051
R=philipj@opera.com

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=185191

[Henrik Steen, 2014-11-11 09:22:00]

henriks@opera.com changed reviewers:
+ fs@opera.com

[philipj_slow, 2014-11-11 10:09:02]

LGTM % nits

https://codereview.chromium.org/710173004/diff/1/LayoutTests/http/tests/media...
File LayoutTests/http/tests/media/media-source/mediasource-seekable.html
(right):

https://codereview.chromium.org/710173004/diff/1/LayoutTests/http/tests/media...
LayoutTests/http/tests/media/media-source/mediasource-seekable.html:15:
mediaElement.pause();
Why is this needed? I can't see what would have made it play.

https://codereview.chromium.org/710173004/diff/1/LayoutTests/http/tests/media...
LayoutTests/http/tests/media/media-source/mediasource-seekable.html:51: //
Append a segment from the middle of the stream to make sure that seekable does
not use buffered.start(0) or duration as first or last value
Nice.

https://codereview.chromium.org/710173004/diff/1/LayoutTests/http/tests/media...
LayoutTests/http/tests/media/media-source/mediasource-seekable.html:61:
assert_less_than(mediaElement.seekable.end(0), mediaElement.duration);
Maybe assert_not_equals instead of these assert_less_than, to match the comment?
That mediaElement.buffered.start(0) > 0 isn't the important fact, AFAICT.

https://codereview.chromium.org/710173004/diff/1/Source/modules/mediasource/M...
File Source/modules/mediasource/MediaSource.cpp (right):

https://codereview.chromium.org/710173004/diff/1/Source/modules/mediasource/M...
Source/modules/mediasource/MediaSource.cpp:378: if (buffered->length() == 0)
The spec doesn't mention this case. If it's impossible, assert so here. If it is
possible, can you file a spec bug to define it?

[Henrik Steen, 2014-11-11 10:42:37]

https://codereview.chromium.org/710173004/diff/1/Source/modules/mediasource/M...
File Source/modules/mediasource/MediaSource.cpp (right):

https://codereview.chromium.org/710173004/diff/1/Source/modules/mediasource/M...
Source/modules/mediasource/MediaSource.cpp:378: if (buffered->length() == 0)
On 2014/11/11 10:09:02, philipj wrote:
> The spec doesn't mention this case. If it's impossible, assert so here. If it
is
> possible, can you file a spec bug to define it?

Filed https://www.w3.org/Bugs/Public/show_bug.cgi?id=27296

[Henrik Steen, 2014-11-12 07:03:10]

The CQ bit was checked by henriks@opera.com

[commit-bot: I haz the power, 2014-11-12 07:03:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/710173004/20001

[commit-bot: I haz the power, 2014-11-12 08:21:27]

Committed patchset #2 (id:20001) as 185191