[PA] Remove `BUILDFLAG(USE_BACKUP_REF_PTR)`

This buildflag is already congruent with
`BUILDFLAG(ENABLE_BACKUP_REF_PTR_SUPPORT)`, provided by PartitionAlloc's
buildflags. This CL trivially migrates all Chromium users to the
PA-sourced buildflag, erasing `BUILDFLAG(USE_BACKUP_REF_PTR)` from the
allocator build recipe.

Bug: 1371729
Change-Id: Ia9488aada1f942500c76e269e863c0e3cea8a546
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4054728
Owners-Override: Bartek Nowierski <[email protected]>
Commit-Queue: Kalvin Lee <[email protected]>
Reviewed-by: Bartek Nowierski <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1076086}
NOKEYCHECK=True
GitOrigin-RevId: d02cbc7640649876b67b022fbb94050c4099e85d
1 file changed
tree: 437728cb314e6946b8131f8cb7be209b5c0f5e7e
  1. asan/
  2. mac/
  3. partition_allocator/
  4. tsan_v2/
  5. OWNERS