Activists are celebrating Sebastián Piñera's historic change of heart
President Sebastián Piñera 'failed to live up to obligations'
Activists hope a vote will take place in coming weeks
Couple’s legal challenge against Civil Registry allowed to continue
Margarette May Macaulay made comments during Dec. 5 hearing in D.C.
Measure garnered renewed attention after Daniela Vega film won Oscar
President Sebastián Piñera has 30 days to sign it
Final vote to take place in country's House of Deputies
Trans person can change name, gender without surgery
Sebastián Piñera’s coalition includes social conservatives