Move download_manager_delegate.h to content. I forgot to move this earlier.

BUG=82782
TBR=rdsmith
Review URL: http://codereview.chromium.org/7631009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@97047 0039d316-1c4b-4281-b951-d872f2087c98
8 files changed