Update comment to match new API.

IGBP AllowAllocation should not be used outside of libgui, Surface
AllowAllocation will do the same. go/warren_buffers

Test: N/A
Flag: EXEMPT no-op change
Bug: 342199002
Change-Id: I5c5b864f7df1b315963e2a39a7869f04b8f4038a
1 file changed