These exist. 
This link is the best place to find all metrics and their definitions:
https://cs.chromium.org/chromium/src/tools/metrics/actions/actions.xml?q=actions.xml&sq=package:chromium&dr&l=11888


MobileTabGridCloseAllRegularTabs: 
User in the iOS tab grid used the Close All control while viewing the regular tabs.

MobileTabGridCloseAllIncognitoTabs: 
User in the iOS tab grid used the Close All control while viewing the incognito tabs.

MobileTabGridUndoCloseAllRegularTabs:
User in the iOS tab grid used the Undo control after closing all regular tabs.

[Auto-generated comment by a script] We noticed that this issue is targeted for M-71; it appears the fix may have landed after branch point, meaning a merge might be required. Please confirm if a merge is required here - if so add Merge-Request-71 label, otherwise remove Merge-TBD label. Thanks.

Removed RBS since these metrics already existed.