Revert 52336 - More header cleanup:

- Some cleanup to url_request.h
- Remove task.h from headers that don't need it.
- Remove histogram.h from message_loop.h

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/2986002

TBR=erg@chromium.org
Review URL: http://codereview.chromium.org/2969006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@52343 0039d316-1c4b-4281-b951-d872f2087c98


CrOS-Libchrome-Original-Commit: f1d9428ecf3a598fb8bc86c9e1f8707dc6bd73cb
6 files changed
tree: 731899819976188dc1868f00e77fd6519c41d1f9
  1. base/
  2. build/
  3. ipc/
  4. testing/