Revert of media: Pass SetCdmReadyCB in {Audio|Video}Decoder::Initialize().

Revert of media: Pass SetCdmReadyCB in {Audio|Video}Decoder::Initialize(). (patchset #2 id:20001 of https://codereview.chromium.org/1442933002/ )

Reason for revert:
Mac build doesn't compile.

../../media/cast/sender/h264_vt_encoder_unittest.cc:140:43: error: too few arguments to function call, expected 5, have 4
                   base::Unretained(this)));
                                          ^
../../media/filters/ffmpeg_video_decoder.h:42:3: note: 'Initialize' declared here
  void Initialize(const VideoDecoderConfig& config,
  ^
1 error generated.

Original issue's description:
> media: Pass SetCdmReadyCB in {Audio|Video}Decoder::Initialize().
>
> This enables all audio/video decoders the ability to get access to the CDM
> associated with the media element. This is useful for certain decoders to handle
> encrypted streams.
>
> For Decrypting{Audio|Video}Decoder and DecryptingDemuxerStream, the SetCdmReadyCB
> is simply moved from constructor to Initialize() call. In the future this could
> also help move Decrypting{Audio|Video}Decoder creation out of DecoderSelector so
> that it is treated the same as all other decoders.
>
> TBR=bbudge@chromium.org
> BUG=545099
>
> Committed: https://crrev.com/406d0255ae170720d2bc68cd7783855f16f3be17
> Cr-Commit-Position: refs/heads/master@{#359702}

TBR=jrummell@chromium.org,dalecurtis@chromium.org,ddorwin@chromium.org,bbudge@chromium.org,xhwang@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=545099
Committed: https://crrev.com/0c1df0a37a815953d1af3d4eaf145af969210d5d
Cr-Commit-Position: refs/heads/master@{#359731}

[loyso (OOO), 2015-11-14 01:46:04]

Created Revert of media: Pass SetCdmReadyCB in
{Audio|Video}Decoder::Initialize().

[commit-bot: I haz the power, 2015-11-14 01:46:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1446713003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1446713003/1

[commit-bot: I haz the power, 2015-11-14 01:48:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-14 01:50:05]

Patchset 1 (id:??) landed as
https://crrev.com/0c1df0a37a815953d1af3d4eaf145af969210d5d
Cr-Commit-Position: refs/heads/master@{#359731}

[xhwang, 2015-11-14 05:37:40]

lgtm

thanks for the revert!

but, why this isn't caught by any bot?