This directory provide Dawn a “no-op” partition_alloc implementation of raw_ptr. This is used only when dawn_partition_alloc_dir is not set.

Why not using the PartitionAlloc “no-op” implementation?

For now, we decided Dawn to provide its own. This allow the partition_alloc dependency to be optional. It makes it easier easier to integrate into other project (Skia, etc...) and build system (CMake, Bazel, etc..)

Moreover, partition_alloc is still depending on chromium‘s //build for now. It means it can only be used inside Dawn who has the same dependency. It can’t be used outside.