Adding some more viz people to cc so they're aware of this proposal. Thanks!

What concrete type would be in the structure? Hopefully not gfx::GpuMemoryBuffer - it should be some simple-ipc type.

Also there were thoughts in the past about replacing the shared bitmaps for compositor transport with GMB. Does that still make sense? Could this be part of that?

I'd like to see unique_ptr<gfx::GpuMemoryBuffer> in the structure as that makes ownership simple. Would that be a problem? 

I think we should be able to replace shared bitmaps with shared memory backed GMBs after adding this.

We can't IPC a pointer, so no pointers please. That would have to be translated into some other type over IPC so it'd be nicer to just put that other thing in the structure. What would that be?

gfx::GpuMemoryBuffer can be transferred over IPC just like base::SharedMemory can. It's an important part of the design of GMBs. GMBs are passed over IPC by acquiring a handle through GMB::GetHandle() on the sender side and then instantiated on the receiving side using GMBF::CreateFromHandle().

I mean, I get that they are transferring, but the pointer is not what we send, there's some more wire-formaty type. That's what should be in TransferableResource, otherwise it contrains how we transport TransferableResource (we cant just send the array as a block of memory for example).

We probably want the GMB handles here in that case but not completely sure what you mean by wire-formaty. FDs can't just sent as a block of memory but I guess they are considered wire-formaty?

GMB instances are not copyable but the handles are so if that's a requirement for TransferableResource then handles are appropriate. Handles leak implementation details and it's much easier to leak memory by mistake when using them. That's why real GMB instances should be preferred whenever possible.

> FDs can't just sent as a block of memory but I guess they are considered wire-formaty?

FDs are integers, which can be memcpy'd, unless I am misunderstanding what you mean by FD?

> GMB instances are not copyable but the handles are so if that's a requirement for TransferableResource then handles are appropriate. Handles leak implementation details and it's much easier to leak memory by mistake when using them. That's why real GMB instances should be preferred whenever possible.

Ok thanks it sounds like handle is what we'd want here.

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