Enable MediaDevices by default

Enable MediaDevices by default by marking the the EnumerateDevices flag as stable.

Note that this includes mediaDevices.enumerateDevices() but also mediaDevices.getUserMedia() which was added later under the same flag.
The Intent to Ships for both were approved recently.

BUG=504280, 503227
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=198529

[Guido Urdaneta, 2015-07-03 12:32:14]

guidou@chromium.org changed reviewers:
+ mkwst@chromium.org

[Mike West, 2015-07-07 11:40:46]

On 2015/07/03 at 12:32:14, guidou wrote:
> 

Can you point me to the thread? I've only found
https://groups.google.com/a/chromium.org/d/msg/blink-dev/709H0911zqM/PqDAvxy6...,
which didn't seem to conclude that shipping was the right course of action.

[Guido Urdaneta, 2015-07-07 14:36:05]

On 2015/07/07 11:40:46, Mike West wrote:
> On 2015/07/03 at 12:32:14, guidou wrote:
> > 
> 
> Can you point me to the thread? I've only found
>
https://groups.google.com/a/chromium.org/d/msg/blink-dev/709H0911zqM/PqDAvxy6...,
> which didn't seem to conclude that shipping was the right course of action.
That was an earlier intent. 
For the latest discussion for mediaDevices.enumerateDevices(), see:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/rB8fgNxpQCA

For mediaDevices.getUserMedia():
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/qUOfAge9qnk

[Mike West, 2015-07-08 07:45:01]

On 2015/07/07 at 14:36:05, guidou wrote:
> On 2015/07/07 11:40:46, Mike West wrote:
> > On 2015/07/03 at 12:32:14, guidou wrote:
> > > 
> > 
> > Can you point me to the thread? I've only found
> >
https://groups.google.com/a/chromium.org/d/msg/blink-dev/709H0911zqM/PqDAvxy6...,
> > which didn't seem to conclude that shipping was the right course of action.
> That was an earlier intent. 
> For the latest discussion for mediaDevices.enumerateDevices(), see:
> https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/rB8fgNxpQCA
> 
> For mediaDevices.getUserMedia():
> https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/qUOfAge9qnk

Ok. LGTM, assuming that the chromium-side interface is going to go through a
security/privacy review.

[Guido Urdaneta, 2015-07-08 17:58:28]

The CQ bit was checked by guidou@chromium.org

[commit-bot: I haz the power, 2015-07-08 17:58:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1217273009/60001

[commit-bot: I haz the power, 2015-07-08 19:21:04]

Committed patchset #4 (id:60001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=198529