avoid poster flicker during video looping or random seek operation

avoid poster flicker during video looping or random seek operation

BUG=340853
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=171846

[Srirama, 2014-04-08 14:34:41]

Flickering happens when video restarts because of loop attribute or when user
does random seek operation.
In the above two cases the display mode is not poster.
So i have added a check so that PosterWaitingForVideo display mode can be set
only if the old display mode is Poster.
With this patch flickering is not seen.
Please have a look at the changes.

[Srirama, 2014-04-09 09:09:09]

PTAL

[scherkus (not reviewing), 2014-04-10 18:30:37]

do you know whether writing a layout test is feasible?

[Srirama, 2014-04-11 04:41:08]

On 2014/04/10 18:30:37, scherkus wrote:
> do you know whether writing a layout test is feasible?

I am not sure, please let me know if layout test is required for this case, if
it is then i will try to add a layout test. Also let me know of any existing
layout test which i can refer. I will also check from the existing media test
cases.

[Srirama, 2014-04-14 07:33:53]

On 2014/04/11 04:41:08, Srirama wrote:
> On 2014/04/10 18:30:37, scherkus wrote:
> > do you know whether writing a layout test is feasible?
> 
> I am not sure, please let me know if layout test is required for this case, if
> it is then i will try to add a layout test. Also let me know of any existing
> layout test which i can refer. I will also check from the existing media test
> cases.

Hi, I have tried writing a test case, but i am not able to capture the 
poster flickering through javascript events. When loop attribute is specified
some of the events are not firing and even if i remove loop attribute and 
restart video with events then flickering is not seen.
Please suggest me if there is a way to write a test case for this or
let me know if i can check in the patch without test case.

[acolwell GONE FROM CHROMIUM, 2014-04-16 15:13:58]

lgtm

[Srirama, 2014-04-17 06:01:28]

The CQ bit was checked by srirama.m@samsung.com

[commit-bot: I haz the power, 2014-04-17 06:01:35]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/srirama.m@samsung.com/228703002/1

[commit-bot: I haz the power, 2014-04-17 07:07:43]

Change committed as 171846