Question about integrating WebGPU into chromium

Hi, WebGPU team

This is Qian Qian from Alibaba Group, I'm leader of Alibaba's 3D engine team

We're developing an advanced 3d rendering engine, and I'm very excited for the possiblity of putting it on browser
I'd like to put my team into a chromium-dawn integration test to help developing of WebGPU, there's some question I wish someone would enlighten me before we start developing

This is my understanding of current chromium gpu process

Suppose we use a Vulkan backend for webgpu, we then need to do
1. Replace GPU process GL-backend with dawn's Vulkan-backend
2. CCRenderDawn (CCRenderVulkan) for compositor
3. Translate all WebGL commands by Angle ? 
Correct me if I'm wrong
 

If this is the way we should take, then we'll need Angle for every platform ? dx12, metal, vulkan ?
And translating webgl to dx12, metal, vulkan, doesn't seem so efficient