Linux: Fix about:memory for SUID sandbox + pid namespaces.
Linux: Fix about:memory for SUID sandbox + pid namespaces.

BUG=36934
TEST=about:memory works on Linux machines with pid namespaces enabled.
Review URL: http://codereview.chromium.org/752001

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@41075 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