Revert "Metal: Add CommandRecordingContext"

This reverts commit 2b3975f808fd6f5afc5a52e58a3dcd5e73984b17.

Reason for revert: causes the failure in

Original change's description:
> Metal: Add CommandRecordingContext
> Introduces the idea of a CommandRecordingContext to the Metal backend,
> similar to other backends. This is a class to track which Metal encoder
> is open on the device-global pending MTLCommandBuffer.
> It will be needed to open/close encoders for lazy clearing.
> Bug: dawn:145
> Change-Id: Ief6b71a079d73943677d2b61382d1c36b88a4f87
> Reviewed-on:
> Reviewed-by: Corentin Wallez <>
> Reviewed-by: Kai Ninomiya <>
> Commit-Queue: Austin Eng <>,,

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: dawn:145
Bug: chromium:1041358
Change-Id: I05c76cd96f723230d05cff65127dc8513d5e03c5
Commit-Queue: Corentin Wallez <>
Reviewed-by: Corentin Wallez <>
8 files changed
tree: dfcaa1f7c4197740296cea417f13b2209000c38e
  1. .clang-format
  2. .gitattributes
  3. .gitignore
  4. .gn
  8. DEPS
  10. OWNERS
  12. README.chromium
  14. build_overrides/
  15. codereview.settings
  16. dawn.json
  17. dawn_wire.json
  18. docs/
  19. examples/
  20. generator/
  21. infra/
  22. scripts/
  23. src/
  24. third_party/

Dawn, a WebGPU implementation

Dawn is an open-source and cross-platform implementation of the work-in-progress WebGPU standard. More precisely it implements webgpu.h that is a one-to-one mapping with the WebGPU IDL. Dawn is meant to be integrated as part of a larger system and is the underlying implementation of WebGPU in Chromium.

Dawn provides several WebGPU building blocks:

  • WebGPU C/C++ headers that applications and other building blocks use.
    • The webgpu.h version that Dawn implements.
    • A C++ wrapper for the webgpu.h.
  • A “native” implementation of WebGPU using platforms' GPU APIs:
    • D3D12 on Windows 10
    • Metal on macOS and iOS
    • Vulkan on Windows, Linux, ChromeOS, Android and Fuchsia
    • OpenGL as best effort where available
  • A client-server implementation of WebGPU for applications that are in a sandbox without access to native drivers

Helpful links:

Documentation table of content

Developer documentation:

User documentation: (TODO, figure out what overlaps with webgpu.h docs)




Apache 2.0 Public License, please see LICENSE.


This is not an officially supported Google product.