The checks are not reliable for Rvalue references, and only are
allowing default/deleted constructors. They are based on the google3
internal rules which do not exactly match our own c++11 rules, and
may diverge more over time.

Email thread that led to this change here: https://groups.google.com/a/chromium.org/forum/#!topic/cxx/9TZvt8vyeEM

R=agable@chromium.org

Review URL: https://codereview.chromium.org/1573663003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@298202 0039d316-1c4b-4281-b951-d872f2087c98