Add MediaSession runtime flag along with stub MediaSession object

Add MediaSession runtime flag along with stub MediaSession object

Implementation of the MediaSession specification will happen behind
the runtime flag 'MediaSession'.

Add a virtual testsuite for running tests with MediaSession flag. This
way we don't have to have the flag enabled when running LayoutTests in
general, only when running MediaSession tests.

Intent to implement:

https://groups.google.com/a/chromium.org/d/msg/blink-dev/dLWDxYgxzQ8/vXt0ntWFNBwJ

BUG=497735
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=198049

[davve, 2015-06-25 15:21:59]

davve@opera.com changed reviewers:
+ philipj@opera.com

[davve, 2015-06-25 15:22:00]

The basic stubs for MediaSession.activate() and MediaSession.release(). There
are outstanding issues about these two, so we'll have some spec impedance going
forward.

https://github.com/whatwg/mediasession/issues/47
https://github.com/whatwg/mediasession/issues/50

But let's try implement them from modules/ (behind flag) to see how far we get.

[davve, 2015-06-25 15:24:29]

On 2015/06/25 15:22:00, David Vest wrote:
> The basic stubs for MediaSession.activate() and MediaSession.release(). There
> are outstanding issues about these two, so we'll have some spec impedance
going
> forward.
> 
> https://github.com/whatwg/mediasession/issues/47
> https://github.com/whatwg/mediasession/issues/50
> 
> But let's try implement them from modules/ (behind flag) to see how far we
get.

MediaSession.activate() and MediaSession.decativate(), I mean. (but it's called
release() in spec. duh.)

[philipj_slow, 2015-06-26 11:56:59]

philipj@opera.com changed reviewers:
+ avayvod@chromium.org, mlamouri@chromium.org

[philipj_slow, 2015-06-26 11:56:59]

Merging this with https://codereview.chromium.org/1208963002/ would make sense I
think.

modules/mediasession will also need OWNERS, and the four of us developers who
have been involved seems like a reasonable start, unless mlamouri or avayvod
says no :)

https://codereview.chromium.org/1206283002/diff/40001/Source/modules/mediases...
File Source/modules/mediasession/MediaSession.idl (right):

https://codereview.chromium.org/1206283002/diff/40001/Source/modules/mediases...
Source/modules/mediasession/MediaSession.idl:5: interface MediaSession {
The usual thing is to put the ] on the same line as "interface", although
certainly not in specs, just in Blink :/

[philipj_slow, 2015-06-26 12:34:41]

https://codereview.chromium.org/1206283002/diff/80001/LayoutTests/media/media...
File LayoutTests/media/mediasession/mediasession-constructor.html (right):

https://codereview.chromium.org/1206283002/diff/80001/LayoutTests/media/media...
LayoutTests/media/mediasession/mediasession-constructor.html:2: <title>Test that
the media session constructor exists</title>
Maybe just "MediaSession() constructor" as this test will likely evolve to also
test the behavior of the no-argument constructor, where some attribute (maybe
transient) can be different. (There's also the Simon Pieters-influenced idea
that the title should describe what is being tested, not what the expected
behavior is.)

https://codereview.chromium.org/1206283002/diff/80001/LayoutTests/media/media...
LayoutTests/media/mediasession/mediasession-constructor.html:12: var
mediaSession = new MediaSession();
Maybe assert_true(mediaSession instanceof MediaSession) for extra paranoia and
to not leave mediaSession unused.

[davve, 2015-06-26 12:50:50]

PTAL

https://codereview.chromium.org/1206283002/diff/40001/Source/modules/mediases...
File Source/modules/mediasession/MediaSession.idl (right):

https://codereview.chromium.org/1206283002/diff/40001/Source/modules/mediases...
Source/modules/mediasession/MediaSession.idl:5: interface MediaSession {
On 2015/06/26 11:56:59, philipj wrote:
> The usual thing is to put the ] on the same line as "interface", although
> certainly not in specs, just in Blink :/

Done.

https://codereview.chromium.org/1206283002/diff/80001/LayoutTests/media/media...
File LayoutTests/media/mediasession/mediasession-constructor.html (right):

https://codereview.chromium.org/1206283002/diff/80001/LayoutTests/media/media...
LayoutTests/media/mediasession/mediasession-constructor.html:2: <title>Test that
the media session constructor exists</title>
On 2015/06/26 12:34:40, philipj wrote:
> Maybe just "MediaSession() constructor" as this test will likely evolve to
also
> test the behavior of the no-argument constructor, where some attribute (maybe
> transient) can be different. (There's also the Simon Pieters-influenced idea
> that the title should describe what is being tested, not what the expected
> behavior is.)

Done.

https://codereview.chromium.org/1206283002/diff/80001/LayoutTests/media/media...
LayoutTests/media/mediasession/mediasession-constructor.html:12: var
mediaSession = new MediaSession();
On 2015/06/26 12:34:41, philipj wrote:
> Maybe assert_true(mediaSession instanceof MediaSession) for extra paranoia and
> to not leave mediaSession unused.

Done.

[philipj_slow, 2015-06-26 12:58:36]

LGTM \o/

Anton and Mounir, do you want to review as well? There will probably be a lot of
patches in total, do you want to arrange it such that we review each other
patches so that we're all in sync, or would you prefer something else?

[mlamouri (slow - plz ping), 2015-06-29 10:28:31]

lgtm with comment addressed

https://codereview.chromium.org/1206283002/diff/100001/LayoutTests/virtual/me...
File
LayoutTests/virtual/mediasession/media/mediasession/mediasession-constructor-expected.txt
(right):

https://codereview.chromium.org/1206283002/diff/100001/LayoutTests/virtual/me...
LayoutTests/virtual/mediasession/media/mediasession/mediasession-constructor-expected.txt:3:
Harness: the test ran to completion.
I don't think you need expected.txt files for passing testharness tests.

[mlamouri (slow - plz ping), 2015-06-29 10:28:51]

On 2015/06/26 at 12:58:36, philipj wrote:
> LGTM \o/
> 
> Anton and Mounir, do you want to review as well? There will probably be a lot
of patches in total, do you want to arrange it such that we review each other
patches so that we're all in sync, or would you prefer something else?

sgtm! :)

[davve, 2015-06-29 10:45:52]

https://codereview.chromium.org/1206283002/diff/100001/LayoutTests/virtual/me...
File
LayoutTests/virtual/mediasession/media/mediasession/mediasession-constructor-expected.txt
(right):

https://codereview.chromium.org/1206283002/diff/100001/LayoutTests/virtual/me...
LayoutTests/virtual/mediasession/media/mediasession/mediasession-constructor-expected.txt:3:
Harness: the test ran to completion.
On 2015/06/29 10:28:31, Mounir Lamouri wrote:
> I don't think you need expected.txt files for passing testharness tests.

The reason I put this here is because otherwise it fallbacks to the non-virtual
-expected.txt, which obviously doesn't match (since the flag isn't enabled
there).

I mentioned this in the closed https://codereview.chromium.org/1208963002/ but
failed to bring over the information here.

If you know of a way to avoid this, I'm all ears.

https://codereview.chromium.org/1206283002/diff/100001/Source/modules/mediase...
File Source/modules/mediasession/MediaSession.idl (right):

https://codereview.chromium.org/1206283002/diff/100001/Source/modules/mediase...
Source/modules/mediasession/MediaSession.idl:1: [
Missing licence header. Will add.

[mlamouri (slow - plz ping), 2015-06-29 10:52:40]

https://codereview.chromium.org/1206283002/diff/100001/LayoutTests/virtual/me...
File
LayoutTests/virtual/mediasession/media/mediasession/mediasession-constructor-expected.txt
(right):

https://codereview.chromium.org/1206283002/diff/100001/LayoutTests/virtual/me...
LayoutTests/virtual/mediasession/media/mediasession/mediasession-constructor-expected.txt:3:
Harness: the test ran to completion.
On 2015/06/29 at 10:45:52, David Vest wrote:
> On 2015/06/29 10:28:31, Mounir Lamouri wrote:
> > I don't think you need expected.txt files for passing testharness tests.
> 
> The reason I put this here is because otherwise it fallbacks to the
non-virtual -expected.txt, which obviously doesn't match (since the flag isn't
enabled there).
> 
> I mentioned this in the closed https://codereview.chromium.org/1208963002/ but
failed to bring over the information here.
> 
> If you know of a way to avoid this, I'm all ears.

Hmm, indeed, it might be tricky. Is the presubmit hook complaining about this
file? I guess I'm fine as long as the presubmit hook is fine ;)

[davve, 2015-06-29 11:16:10]

https://codereview.chromium.org/1206283002/diff/100001/LayoutTests/virtual/me...
File
LayoutTests/virtual/mediasession/media/mediasession/mediasession-constructor-expected.txt
(right):

https://codereview.chromium.org/1206283002/diff/100001/LayoutTests/virtual/me...
LayoutTests/virtual/mediasession/media/mediasession/mediasession-constructor-expected.txt:3:
Harness: the test ran to completion.
On 2015/06/29 10:52:39, Mounir Lamouri wrote:
> On 2015/06/29 at 10:45:52, David Vest wrote:
> > On 2015/06/29 10:28:31, Mounir Lamouri wrote:
> > > I don't think you need expected.txt files for passing testharness tests.
> > 
> > The reason I put this here is because otherwise it fallbacks to the
> non-virtual -expected.txt, which obviously doesn't match (since the flag isn't
> enabled there).
> > 
> > I mentioned this in the closed https://codereview.chromium.org/1208963002/
but
> failed to bring over the information here.
> > 
> > If you know of a way to avoid this, I'm all ears.
> 
> Hmm, indeed, it might be tricky. Is the presubmit hook complaining about this
> file? I guess I'm fine as long as the presubmit hook is fine ;)

The presubmit hook is indeed complaining as I allude to in
https://codereview.chromium.org/1208963002/ (part of why I did the split
initially). This CL is therefore uploaded using --bypass-hooks but I have tried
to eliminate other errors by temporarily removing the -expected.txt file. It's
not a bulletproof procedure though.

Should I file a bug on that (where?) to find out the best course of action?

[davve, 2015-06-30 09:11:05]

On 2015/06/29 11:16:10, David Vest wrote:
> Should I file a bug on that (where?) to find out the best course of action?

The relevant logic of the presubmit hook seems to be inside
check-testharness-expected-pass. I see no trivial way to check for corresponding
non-virtual -expected.txt file and allow overriding passing (silent) ones.

A somewhat ugly work-around around the current system would be to just add a
dummy warning to the test.

[philipj_slow, 2015-06-30 09:42:09]

On 2015/06/30 09:11:05, David Vest wrote:
> On 2015/06/29 11:16:10, David Vest wrote:
> > Should I file a bug on that (where?) to find out the best course of action?
> 
> The relevant logic of the presubmit hook seems to be inside
> check-testharness-expected-pass. I see no trivial way to check for
corresponding
> non-virtual -expected.txt file and allow overriding passing (silent) ones.
> 
> A somewhat ugly work-around around the current system would be to just add a
> dummy warning to the test.

Sure, it's ugly, but I think it's fine since this virtual test suite is slated
to go away when the runtime flag becomes experimental or stable.

[davve, 2015-06-30 09:42:23]

The CQ bit was checked by davve@opera.com

[davve, 2015-06-30 09:42:23]

The patchset sent to the CQ was uploaded after l-g-t-m from philipj@opera.com,
mlamouri@chromium.org
Link to the patchset: https://codereview.chromium.org/1206283002/#ps140001
(title: "Add dummy warning to test, move comment to test and update stale
expected file.")

[commit-bot: I haz the power, 2015-06-30 09:42:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1206283002/140001

[davve, 2015-06-30 09:48:47]

The CQ bit was unchecked by davve@opera.com

[davve, 2015-06-30 09:50:48]

The CQ bit was checked by davve@opera.com

[commit-bot: I haz the power, 2015-06-30 09:51:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1206283002/140001

[commit-bot: I haz the power, 2015-06-30 10:50:41]

Committed patchset #8 (id:140001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=198049