Fixes a null pointer bug, and adds null checks around potentially dying process and channel.
Fixes a null pointer bug, and adds null checks around potentially dying process and channel.

Review URL: http://codereview.chromium.org/7099

git-svn-id: http://src.chromium.org/svn/trunk/src@3268 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 1a17d5e283f8351174674e644ae48544e9cad5f6
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