Clear error state flags in binarystream::rewind().
Clear error state flags in binarystream::rewind().

This patch is taken from the downstream google-breakpad in Chromium OS
(https://gerrit.chromium.org/gerrit/#change,7797), which makes
binarystream::rewind() properly clear error state flags.

BUG=460
TEST=Tested in downstream google-breakpad in Chromium OS.
A=asharif@chromium.org
Review URL: http://breakpad.appspot.com/339001

git-svn-id: 7939527bf0a06ad24ad020f729d5600cb42ed5d7@901 4c0a9323-5329-0410-9bdc-e9ce6186880e

mikewied/breakpad,mikewied/breakpad,mikewied/breakpad,mikewied/breakpad,mikewied/breakpad,mikewied/breakpad