Avoid divide by zero when gathering stats for SDCH
Avoid divide by zero when gathering stats for SDCH

A reordering of stats gathering produced a vulnerability to
divide by zero.

bug=1835317
r=mbelshe
Review URL: http://codereview.chromium.org/113115

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@15578 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