bug #735262 showed that the condition processing of metric values need to not assume multiple AND conditions on the same metric can product the desired effect.

That bug was fixed with the new range condition. For example, rather than creating an alert definition with two conditions with the AND conjunction (aka "ALL):

if metric A > 50
AND
if metric A < 100

instead you can now have one condition with a range:

if 50 < metric A < 100

However, this new range condition only supports absolute metric values.

This issue asks that we add another new type of alert condition to support metric BASELINE ranges. Specifically, we want to go from this:

if metric A max baseline value > 10%
AND
if metric A max baseline value < 30%

we want a new baseline range condition that allows for a single condition that says:

if 10% < metric A max baseline value < 30%

This is to address the same issue that bug #735262 reported.