[Nexus 5 General] KopiJahe:
So, just posted this a while ago at reddit, and some guy over there points out that maybe XDA is better place for this.

I'm just realized this afternoon by looking my android one device (sprout_b, indonesian version).

The Indian version (sprout) got updated to lollipop, and have the new device protection. Even if I flashed and used the said update on my device, I can't use the new device protection.

So I tried to compare both system files and boot.img, and found 1 partition missing on my device, FRP.

I investigated more about this, and it seems that both nexus 6 and 9 got this partition too (under the name PST).

And then, wild sudden clarity appears! FRP = Factory Reset Protection.

So, both my devices (nexus 5 and nexian journey 1 -android one- ) probably didn't receive this protection, because the partition needed for it isn't there.

For more info, here's the fstabs from both android one branch (sprout and sprout_b):

sprout:

# Android fstab file.
#<src> <mnt_point> <type> <mnt_flags and options> <fs_mgr_flags>
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK

/dev/block/platform/mtk-msdc.0/by-name/system /system ext4 ro wait
/dev/block/platform/mtk-msdc.0/by-name/userdata /data ext4 noatime,nosuid,nodev,noauto_da_alloc,discard wait,check,encryptable=/dev/block/platform/mtk-msdc.0/by-name/metadata
/dev/block/platform/mtk-msdc.0/by-name/cache /cache ext4 noatime,nosuid,nodev,noauto_da_alloc,discard wait,check
/dev/block/platform/mtk-msdc.0/by-name/protect1 /protect_f ext4 noatime,nosuid,nodev,noauto_da_alloc,commit=1,nodelalloc wait,check
/dev/block/platform/mtk-msdc.0/by-name/protect2 /protect_s ext4 noatime,nosuid,nodev,noauto_da_alloc,commit=1,nodelalloc wait,check
/dev/block/platform/mtk-msdc.0/by-name/oem /oem ext4 ro,context=u:object_r:oemfs:s0,nosuid,nodev wait
/devices/platform/mtk-msdc.1/mmc_host* auto vfat defaults voldmanaged=sdcard0:auto,noemulatedsd
/dev/block/platform/mtk-msdc.0/by-name/frp /persistent emmc defaults defaults

sprout_b:

# Android fstab file.
#<src> <mnt_point> <type> <mnt_flags and options> <fs_mgr_flags>
# The filesystem that contains the filesystem checker binary (typically /system) cannot
# specify MF_CHECK, and must come before any filesystems that do specify MF_CHECK

/dev/block/platform/mtk-msdc.0/by-name/system /system ext4 ro wait
/dev/block/platform/mtk-msdc.0/by-name/userdata /data ext4 noatime,nosuid,nodev,noauto_da_alloc,discard wait,check,encryptable=/dev/block/platform/mtk-msdc.0/by-name/metadata
/dev/block/platform/mtk-msdc.0/by-name/cache /cache ext4 noatime,nosuid,nodev,noauto_da_alloc,discard wait,check
/dev/block/platform/mtk-msdc.0/by-name/protect1 /protect_f ext4 noatime,nosuid,nodev,noauto_da_alloc,commit=1,nodelalloc wait,check
/dev/block/platform/mtk-msdc.0/by-name/protect2 /protect_s ext4 noatime,nosuid,nodev,noauto_da_alloc,commit=1,nodelalloc wait,check
/dev/block/platform/mtk-msdc.0/by-name/oem /oem ext4 ro,context=u:object_r:oemfs:s0,nosuid,nodev wait
/devices/platform/mtk-msdc.1/mmc_host* auto vfat defaults voldmanaged=sdcard1:auto

FRP is also mentioned in file_contexts file in boot.img:

/dev/block/mmcblk0p18 u:object_r:frp_block_device:s0

So, what do you guys think?