upgrade cache tool: Improve the handling of errors so that we ignore as much as possible without aborting the whole process.
upgrade cache tool: Improve the handling of errors so that
we ignore as much as possible without aborting the whole process.

R=nsylvain

Review URL: http://codereview.chromium.org/12925

git-svn-id: http://src.chromium.org/svn/trunk/src@6334 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 8bf3d285996e702a646cc3ef92fb7556d5607ed1
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser