When the user enters their password after attempting to enable a security-sensitive feature, that enabling action is not immediately performed, until the user flips the toggle again. This is because multidevice_page.js has a defined Auth Token observer method, attemptedEnabledFeature_(), but it's not explicitly declared on the authToken_ property.

How this happened:
This CL [1] which altered password requirements on the Better Together settings page removed the attemptedEnabledFeature_() observer method definition in multidevice_page.js, but not its declaration. Its declaration was subsequently removed in [2]. CL [1] was broken for other reasons, so I reverted it, but wasn't aware of [2], so I incorrectly assumed the attemptedEnabledFeature_() declaration would still be present.

Note that because both [1] and [2] landed in master *after* M70 branch, this breakage is not present in M70 and its fix does not need to be merged.

1) https://chromium-review.googlesource.com/c/chromium/src/+/1200148
2) https://chromium-review.googlesource.com/c/chromium/src/+/1200564