[Blink,RemotePlayback] Use PresentationController for availability

[Blink,RemotePlayback] Use PresentationController for availability

If NewRemotePlaybackPipeline is enabled, RemotePlayback object registers itself
with PresentationController to listen for remote playback devices availability.
It passes it a special URL derived from the media element's source.

BUG=517102
TEST=run virtual/new-remote-playback-pipeline layout tests

[whywhat, 2017-05-17 02:22:22]

The CQ bit was checked by avayvod@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-05-17 02:23:56]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[whywhat, 2017-05-17 02:24:01]

Description was changed from

==========
Availability refactoring proof of concept

BUG=517102
==========

to

==========
Availability refactoring proof of concept

BUG=517102
TEST=run Chrome with "New remote playback pipeline" enabled in chrome://flags;
test that cast button shows up in sync with Cast devices availability (turn wifi
on/off)
==========

[commit-bot: I haz the power, 2017-05-17 03:51:31]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-05-17 03:51:32]

Dry run: Try jobs failed on following builders:
  linux_android_rel_ng on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/linux_androi...)

[whywhat, 2017-05-31 04:06:19]

Description was changed from

==========
Availability refactoring proof of concept

BUG=517102
TEST=run Chrome with "New remote playback pipeline" enabled in chrome://flags;
test that cast button shows up in sync with Cast devices availability (turn wifi
on/off)
==========

to

==========
[Blink,RemotePlayback] Use PresentationController for availability

If NewRemotePlaybackPipeline is enabled, RemotePlayback object registers itself
with PresentationController to listen for remote playback devices availability.
It passes it a special URL derived from the media element's source.

BUG=517102
TEST=run virtual/new-remote-playback-pipeline layout tests
==========

[whywhat, 2017-05-31 04:06:19]

avayvod@chromium.org changed reviewers:
+ mfoltz@chromium.org, mlamouri@chromium.org

[whywhat, 2017-05-31 04:06:52]

The CQ bit was checked by avayvod@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-05-31 04:07:04]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-31 04:27:25]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-05-31 04:27:26]

Dry run: Try jobs failed on following builders:
  linux_chromium_headless_rel on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[mark a. foltz, 2017-05-31 21:16:41]

https://codereview.chromium.org/2890633003/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/html/HTMLMediaElement.cpp (right):

https://codereview.chromium.org/2890633003/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/html/HTMLMediaElement.cpp:1137:
RemotePlaybackClient()->SourceChanged(current_src_);
Is the goal to track the currently playing source or to track all sources listed
in the media element?

https://codereview.chromium.org/2890633003/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.cpp
(right):

https://codereview.chromium.org/2890633003/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.cpp:179: //
pipeline.
So kNotSupported error will not be thrown going forward?  I thought we had
figured out a way to map the enums returned by the PresentationService to meet
the needs of the Remote Playback API.

https://codereview.chromium.org/2890633003/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.cpp:329: // If
we're listening for the previous source, we should stop listening to
Do you want to restrict source URLs considered to file:, http:, https: ?

https://codereview.chromium.org/2890633003/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.cpp:406: //
TODO(avayvod): add and fill more info to the JSON structure.
Can you explain why URL-encoding is not sufficient?  What is the "more info"
that will be required here?

https://codereview.chromium.org/2890633003/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.h (right):

https://codereview.chromium.org/2890633003/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.h:82: const
WebVector<WebURL>& Urls() const override;
Can this method have a more specific name?

https://codereview.chromium.org/2890633003/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/modules/remoteplayback/RemotePlayback.h:127:
WebVector<WebURL> availability_urls_;
Only one element here seems to be used at any one time.

https://codereview.chromium.org/2890633003/diff/20001/third_party/WebKit/publ...
File
third_party/WebKit/public/platform/modules/remoteplayback/WebRemotePlaybackClient.h
(right):

https://codereview.chromium.org/2890633003/diff/20001/third_party/WebKit/publ...
third_party/WebKit/public/platform/modules/remoteplayback/WebRemotePlaybackClient.h:33:
virtual void SourceChanged(const WebURL&) = 0;
What if the media element has multiple <source>s?

[mark a. foltz, 2017-05-31 21:23:26]

I also didn't see any interaction with PresentationController in the current
patchset.