Revert 225961 "Disabled flaky EncryptedMediaIsTypeSupportedPeppe..."

The NOTREACHED() was fixed in r227399.

> Disabled flaky EncryptedMediaIsTypeSupportedPepperCDMRegisteredWithWrongPathTest.PepperCDMsRegisteredButAdapterNotPresent.
> 
> TBR=acolwell@chromium.org
> BUG=301571
> 
> Review URL: https://codereview.chromium.org/25132006

TBR=phoglund@chromium.org,ddorwin@chromium.org

Review URL: https://codereview.chromium.org/26377004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228460 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228460