Ignore "_ignore.txt" files when counting errors we want to fix sometime.
Ignore "_ignore.txt" files when counting errors we want to fix sometime.

BUG=5469
TEST=make sure errors in _ignore files in, say, base/data/purify/ don't show
  up in the buildbot's count of errors we need to fix
Review URL: http://codereview.chromium.org/17457

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@7844 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser