Revert 233816 "Retry on low-level connection errors and on HTTP ..."

BUG=316569

> Retry on low-level connection errors and on HTTP 503 errors in PrivetURLFetcher
> 
> To avoid connection reset issues on long file upload, retry on low-level
> connection errors and HTTP 503 errors in PrivetURLFetcher.
> 
> BUG=
> 
> Review URL: https://codereview.chromium.org/62753004

TBR=noamsml@chromium.org

Review URL: https://codereview.chromium.org/66313006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233860 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233860