Update poster code as per https://html.spec.whatwg.org/#show-poster-flag

Update poster code as per https://html.spec.whatwg.org/#show-poster-flag

Update poster related code as per spec and clean up displayMode()
and setDisplayMode() functions.

BUG=342621

[Srirama, 2015-10-01 09:37:03]

srirama.m@samsung.com changed reviewers:
+ philipj@opera.com

[Srirama, 2015-10-01 09:37:04]

Uploaded the changes from https://codereview.chromium.org/1297983002/ using
chromium repo.
PTAL.

[philipj_slow, 2015-10-01 09:45:59]

It doesn't look like you're setting the show poster flag in the same places
where the spec says. For example, it should be set to true as step 2 of the
resource selection algorithm, right after setting networkState to
NETWORK_NO_SOURCE.

https://codereview.chromium.org/1377353002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/html/HTMLVideoElement.cpp (right):

https://codereview.chromium.org/1377353002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/html/HTMLVideoElement.cpp:188: void
HTMLVideoElement::updateDisplayState(bool forceUpdate)
This whole method looks suspicifous to me, it doesn't correspond to anything in
the spec. It would be good to start out by only using the show poster flag in
precisely the places the spec says, and then see what breaks. Wherever you need
to add something, we probably have a spec to fix as well.

[Srirama, 2015-10-09 14:29:26]

Updated showposter flag as per spec and removed unneeded code. Right now the
following tests are failing. I will investigate one by one and update the
analysis.

media/controls-mute-with-controller.html
media/controls-restrained-media-controller.html
media/track/track-webvtt-two-cue-layout-after-first-end.html
media/video-canvas-alpha.html
media/video-no-audio.html
media/video-poster.html
media/video-zoom.html

[philipj_slow, 2015-11-16 14:24:14]

I take it that this is not waiting for my review right now, but please ping me
when I should take another look.

[foolip, 2016-05-25 10:22:20]

foolip@chromium.org changed reviewers:
+ foolip@chromium.org
- philipj@opera.com

[foolip, 2016-05-25 10:22:55]

This is my new account, I'll add myself to some of your reviews, feel free to
send media element reviews my way.

[Srirama, 2016-05-25 10:42:27]

On 2016/05/25 10:22:55, Philip Jägenstedt wrote:
> This is my new account, I'll add myself to some of your reviews, feel free to
> send media element reviews my way.

Welcome back, surely will add you.