Move creation and ownership of DownloadManager from the embedder to content. This matches all the other objects that content depends on.

In a followup change, I'll make content support NULL DownloadManagerDelegates to match the rest of the delegate interfaces.

BUG=98716
Review URL: https://chromiumcodereview.appspot.com/10535026

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@140761 0039d316-1c4b-4281-b951-d872f2087c98
46 files changed