Add two new crash signatures to known_crashes.txt.
Add two new crash signatures to known_crashes.txt.

BUG=73055,73059
TEST=Green win-reliability bot.
Review URL: http://codereview.chromium.org/6524022

git-svn-id: http://src.chromium.org/svn/trunk/src@75002 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 63c47b6580a468c29c45ba4364e1625a441d1f3e
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