commit eeba8fdff6bca1f99389bcf71511a3f11a6867cb
author etiennep-chromium <etiennep@chromium.org> Fri Sep 19 11:51:46 2025
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Fri Sep 19 11:51:46 2025
tree 640644fcde8b7a41e53419343b06ee6eb5e8b0ec
parent 6a24fbdd833f4d4dc213c635503240c94090e6ad

[GC] Use context size in external memory

When adding stricter limits on external v8 memory, I hit test failure:
https://chromium-review.googlesource.com/c/v8/v8/+/6942837
(reporting 200Gb memory)

This is because HTMLCanvasElement::UpdateMemoryUsage isn't accurate
for webgl context.
This CL makes a few incremental steps to make UpdateMemoryUsage more accurate:
- Use DrawingBufferSize instead of host's size; ultimately this is what fixes the issue above for webgl.
- It also moves UpdateMemoryUsage around to makes sure it's
invoked after context_->Reshape().
- Consider memory=0 when there's no context.
- Every type of context is included in HTMLCanvasElement: this aligns with OffscreenCanvas: this uses a default impl AllocatedBufferCountPerPixel() == 1 which is a no-op in OffscreenCanvas; the caveat is that this isn't accurate for all context.

Other changes that will be done in follow-up:
- Merge OffscreenCanvas and HTMLCanvasElement impl of UpdateMemoryUsage
- Improve AllocatedBufferCountPerPixel for more context (e.g. OffscreenCanvasRenderingContext2D should get the same behavior as CanvasRenderingContext2D through their common base class)

Bug: 361124432
Change-Id: I03dcf8a13f293e2fda7ad28164b230b3f4967622
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6950799
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Jean-Philippe Gravel <jpgravel@chromium.org>
Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1517859}