Accept up to 60fps frame rate in MediaStreamVideoCapturerSource

Accept up to 60fps frame rate in MediaStreamVideoCapturerSource.

MSVCS has a list of by-default supported capture formats |kVideoFormats|
used as a fallback for sources that don't support capability
enumeration. It's composed of a couple of resolutions and a fixed frame
rate of 30.

This CL adds also 60 fps to the fallback list, so the user can select
frame rates over 30, e.g. by setting min=54 and max=54.

BUG=381225
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=275290

[mcasas, 2014-06-05 17:26:06]

dalecurtis@ PTAL.

(tommi@ FYI).

[DaleCurtis, 2014-06-05 18:01:50]

I'm not the right primary reviewer for this.  You should find someone on the
capture side.  Technically this looks good to me, but I can see how it would
have unintended consequences.

[tommi (sloooow) - chröme, 2014-06-05 19:58:00]

lgtm.  Dale - what are the unforeseen consequences you're thinking of?

Miguel - can you update the description to mention 60fps explictly since that's
the only new frame rate that's being added.

[DaleCurtis, 2014-06-05 20:06:33]

I probably just don't understand this code, which is another reason I shouldn't
be the primary reviewer :)

From my naive view hand wavy-view, it seems like previous sources which may have
been picked up at 30fps may now match against the 60fps values.  That may be
fine or may introduce new issues.

[mcasas, 2014-06-05 20:39:15]

On 2014/06/05 20:06:33, DaleCurtis wrote:
> I probably just don't understand this code, which is another reason I
shouldn't
> be the primary reviewer :)
> 
> From my naive view hand wavy-view, it seems like previous sources which may
have
> been picked up at 30fps may now match against the 60fps values.  That may be
> fine or may introduce new issues.

Basically this CL just gives more control to the user in cases
where the source does not inform of capabilities... this is the
case with a number of non-UVC cameras.  Before this change
the (power) user would not be able to force >30 fps even
though the HW might support it... but the fallback frame rate
is still 30fps.

[mcasas, 2014-06-05 20:40:05]

The CQ bit was checked by mcasas@chromium.org

[commit-bot: I haz the power, 2014-06-05 20:42:44]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mcasas@chromium.org/311363002/40001

[commit-bot: I haz the power, 2014-06-06 01:16:07]

Change committed as 275290