SLOW QUERY LOG - Group queries and check total slow query

Hi again guys
slow log is a very very good tool to know what´s running slow and change 'bad' queries
the problem is the slow query time isn´t a fixed time in real life, it must be a dinamic value
for example i know that i have some queries that they can´t be done more than 1 second, well what i´m talking about?

first... a per query estimate time tweak like:
/*estimate time=5ms*/ SELECT * FROM any_table WHERE some where that must run before 5ms

second... a per group of queries time tweak like:
1) /*group query time=1s*/
2) do one query
3) do another query
4) do another query
5) do another query
6) /*end group of query slow query estimate time*/

if 2+3+4+5+6 total time is bigger than group query time, this should be logged

that´s very nice and very useful since a group of queries = a php or another web application page information/action and...
only one query = a simple query information request or a update/delete/create/insert data append/change

with this two types of query could allow a very very powerfull tool to undestand where my database is slowing down, it´s on only one query? or a group of queries that didn´t done the task in a good time?

check that doesnt matter about cliente time to retrieve query results, just server query process time...