Implement MediaSource support for mojo.

Implement MediaSource support for mojo.

- Implements WebMimeRegistryImpl::supportsMediaSourceMIMEType().
- Changes NullEncryptedMediaPlayerSupport to return a callback
  bound to NOTIMPLEMENTED() for the NeedKeyCB.

BUG=423416
TEST=basic mse player plays!

Committed: https://crrev.com/328d4822fc471b4fa3c137656758db752bbb749d
Cr-Commit-Position: refs/heads/master@{#300012}

[DaleCurtis, 2014-10-14 21:30:33]

Patchset #1 (id:1) has been deleted

[DaleCurtis, 2014-10-14 21:32:32]

dalecurtis@chromium.org changed reviewers:
+ jamesr@chromium.org, xhwang@chromium.org

[DaleCurtis, 2014-10-14 21:32:32]

isTypeSupported() implementation stolen from
https://code.google.com/p/chromium/codesearch#chromium/src/content/renderer/r...

[xhwang, 2014-10-15 03:52:35]

Great! LGTM

[DaleCurtis, 2014-10-16 18:21:12]

jamesr: ping?

[jamesr, 2014-10-16 18:24:01]

mojo/ lgtm

https://codereview.chromium.org/653213002/diff/20001/media/blink/null_encrypt...
File media/blink/null_encrypted_media_player_support.cc (right):

https://codereview.chromium.org/653213002/diff/20001/media/blink/null_encrypt...
media/blink/null_encrypted_media_player_support.cc:13: static void
NeedKeyHandler(const std::string& type,
i think instead of static putting this in a anonymous namespace would be better
so you don't collide with anything that someone else wants to put in namespace
media with this name

[DaleCurtis, 2014-10-16 18:29:50]

Thanks for review!

https://codereview.chromium.org/653213002/diff/20001/media/blink/null_encrypt...
File media/blink/null_encrypted_media_player_support.cc (right):

https://codereview.chromium.org/653213002/diff/20001/media/blink/null_encrypt...
media/blink/null_encrypted_media_player_support.cc:13: static void
NeedKeyHandler(const std::string& type,
On 2014/10/16 18:24:01, jamesr wrote:
> i think instead of static putting this in a anonymous namespace would be
better
> so you don't collide with anything that someone else wants to put in namespace
> media with this name

media code typically prefers the static prefix to anonymous namespace, but since
this is EME code I defer to whatever xhwang@ wants.

[xhwang, 2014-10-16 21:24:51]

On 2014/10/16 18:29:50, DaleCurtis wrote:
> Thanks for review!
> 
>
https://codereview.chromium.org/653213002/diff/20001/media/blink/null_encrypt...
> File media/blink/null_encrypted_media_player_support.cc (right):
> 
>
https://codereview.chromium.org/653213002/diff/20001/media/blink/null_encrypt...
> media/blink/null_encrypted_media_player_support.cc:13: static void
> NeedKeyHandler(const std::string& type,
> On 2014/10/16 18:24:01, jamesr wrote:
> > i think instead of static putting this in a anonymous namespace would be
> better
> > so you don't collide with anything that someone else wants to put in
namespace
> > media with this name
> 
> media code typically prefers the static prefix to anonymous namespace, but
since
> this is EME code I defer to whatever xhwang@ wants.

There was a long debate about static vs anonymous namespace and I think we
prefer static. But this is not a hard rule. In a lot of cases we do use
anonymous namespaces.

lgtm++ with the current CL

[DaleCurtis, 2014-10-16 21:26:33]

Thanks for review everyone!

[DaleCurtis, 2014-10-16 21:26:41]

The CQ bit was checked by dalecurtis@chromium.org

[commit-bot: I haz the power, 2014-10-16 21:27:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/653213002/20001

[commit-bot: I haz the power, 2014-10-16 23:43:52]

Committed patchset #1 (id:20001)

[commit-bot: I haz the power, 2014-10-16 23:44:29]

Patchset 1 (id:??) landed as
https://crrev.com/328d4822fc471b4fa3c137656758db752bbb749d
Cr-Commit-Position: refs/heads/master@{#300012}