Revert "Clean up dns prefetch code, and also port it."
This reverts commit r9312.

Revert "Fix HostResolver crash when MessageLoop is destroyed during"
This reverts commit r9317.

BUG=5687,6683

TBR=ph

Review URL: http://codereview.chromium.org/21133


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@9325 0039d316-1c4b-4281-b951-d872f2087c98
14 files changed