Add techcrunch.com pages to mobile_memory page set.

This CL adds a few navigations on the same domain (techcrunch.com) to test
renderer process memory bloat.

Overall private dirty of the page set should now capture the upcoming
improvements in the Blink resource cache (specifically the fact that it will
use discardable memory).

BUG=290193
R=clamy@chromium.org, tonyg@chromium.org

Review URL: https://codereview.chromium.org/170453002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252546 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 252546
Added in-session captive portal notification.

BUG=240237
TEST=unit_tests:NetworkPortalDetectorNotification*

Review URL: https://codereview.chromium.org/171423005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@252547 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 252547