Remove the old WebMediaSourceImpl::addSourceBuffer overload

Remove the old WebMediaSourceImpl::addSourceBuffer overload

Complete the transition to using the new addSourceBuffer overload
that takes codecs as an unparsed string.

BUG=none

Committed: https://crrev.com/b1fc55eebc36abcb85e5f6859914f7d90efcbd1d
Cr-Commit-Position: refs/heads/master@{#343477}

[servolk, 2015-08-14 00:05:36]

servolk@chromium.org changed reviewers:
+ wolenetz@chromium.org

[wolenetz, 2015-08-14 20:13:30]

lgtm % s/WebSourceBufferImpl/WebMediaSourceImpl/ in CL description. Thanks again
for doing this code coalescence!

[servolk, 2015-08-14 20:23:14]

On 2015/08/14 20:13:30, wolenetz wrote:
> lgtm % s/WebSourceBufferImpl/WebMediaSourceImpl/ in CL description. Thanks
again
> for doing this code coalescence!

done

[servolk, 2015-08-14 20:23:17]

The CQ bit was checked by servolk@chromium.org

[commit-bot: I haz the power, 2015-08-14 20:23:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1282883004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1282883004/20001

[commit-bot: I haz the power, 2015-08-14 20:28:42]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-08-14 20:29:39]

Patchset 2 (id:??) landed as
https://crrev.com/b1fc55eebc36abcb85e5f6859914f7d90efcbd1d
Cr-Commit-Position: refs/heads/master@{#343477}