Remove WebMediaPlayerImpl::ContentDecryptionModuleAttached().

Remove WebMediaPlayerImpl::ContentDecryptionModuleAttached().

The method declaration in the header file was left over in e2ea518 when
EME related code was moved to EncryptedMediaSupportImpl.

TBR=acolwell

Committed: https://crrev.com/dc8c0c4083a6e4b8e75ce1748c3341583f7e51b6
Cr-Commit-Position: refs/heads/master@{#293264}

[scherkus (not reviewing), 2014-09-03 22:14:51]

scherkus@chromium.org changed reviewers:
+ acolwell@chromium.org

[scherkus (not reviewing), 2014-09-03 22:14:57]

The CQ bit was checked by scherkus@chromium.org

[commit-bot: I haz the power, 2014-09-03 23:24:09]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/scherkus@chromium.org/537193002/1

[commit-bot: I haz the power, 2014-09-04 02:24:04]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-09-04 02:24:05]

Try jobs failed on following builders:
  android_clang_dbg_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_clang_d...)
  android_dbg_tests_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tes...)

[scherkus (not reviewing), 2014-09-04 03:27:07]

The CQ bit was checked by scherkus@chromium.org

[commit-bot: I haz the power, 2014-09-04 03:28:29]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/scherkus@chromium.org/537193002/1

[commit-bot: I haz the power, 2014-09-04 04:14:08]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-09-04 04:14:09]

Try jobs failed on following builders:
  android_clang_dbg_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_clang_d...)

[scherkus (not reviewing), 2014-09-04 04:24:17]

The CQ bit was checked by scherkus@chromium.org

[commit-bot: I haz the power, 2014-09-04 04:29:13]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/scherkus@chromium.org/537193002/1

[commit-bot: I haz the power, 2014-09-04 05:24:48]

Committed patchset #1 (id:1) as 82fc6bd87b789799a931b075b337c9714edde77a

[commit-bot: I haz the power, 2014-09-10 03:30:00]

Patchset 1 (id:??) landed as
https://crrev.com/dc8c0c4083a6e4b8e75ce1748c3341583f7e51b6
Cr-Commit-Position: refs/heads/master@{#293264}