Prepare to revert WebKit patch http://trac.webkit.org/changeset/68310 because of stability issues (race conditions detected by tsan, possibly leading to crashes).

      Revert &quotUpdate sqlite's README.chromium with a note to keep webkit side&quot (http://crrev.com/62151).

Revert &quotRemove our local modifications to sqlite's os_unix.c now that&quot (http://crrev.com/60761).

BUG=70589, 22208
TEST=none

Review URL: http://codereview.chromium.org/6330011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@72673 0039d316-1c4b-4281-b951-d872f2087c98