Add Network Connectivity Diagnostics UMA entries to histograms.xml

BUG=271137
R=isherman@chromium.org

Review URL: https://codereview.chromium.org/51213009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233911 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233911
[Telemetry] Fix memory.top_25 timeouts.

Apparently, the click_element action now waits for navigation itself. So we
can't have an explicit wait for navigation after that action. Otherwise it just
waits for a navigation that never comes.

BUG=316491

Review URL: https://codereview.chromium.org/59903014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233912 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233912