Revert 236174 "Reland r235494: Create and configure CastSender P..."

Looks like this part's likely causing Mac size regression:
http://build.chromium.org/p/chromium/builders/Mac/builds/23246

> Reland r235494: Create and configure CastSender Part 2
> 
> Relanding the second half of the change.
> 
> BUG=301920
> TBR=scherkus
> 
> Review URL: https://codereview.chromium.org/76733002

TBR=hclam@chromium.org

Review URL: https://codereview.chromium.org/77713002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236189 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236189