Molten Wildebeest's Gizzard absorb shield question

How does Molten Wildebeest’s Gizzard absorption shield works? It refreshes every 4 seconds if not taken damage. But what not taken damage means?

  1. Your did not take any damage = your HP did not drop even 1 point = you did not lost even 1 HP.
  2. Same as 1 + your shield did not took (absorb) any damage.

Which is it? 1 or 2?

98% sure it is 2. It does go down when you get hit, but it might just be because the shielding value is so low compared to other options on wizard