Filing as a good first bug to learn workflows.

The following WebRender debug preferences are defined but never read. They are not present in the GFX_WEBRENDER_DEBUG flag table in gfx/thebes/gfxPlatform.cpp, and nothing else reads them. Please remove their definitions.

• gfx.webrender.debug.alpha-primitives in modules/libpref/init/all.js
• gfx.webrender.debug.slow-frame-indicator in modules/libpref/init/all.js
• gfx.webrender.debug.slow-cpu-frame-threshold in modules/libpref/init/StaticPrefList.yaml (remove the whole entry: name/type/value/mirror lines)

Link to the code:
https://searchfox.org/mozilla-central/source/modules/libpref/init/all.js#404
https://searchfox.org/mozilla-central/source/modules/libpref/init/all.js#412
https://searchfox.org/mozilla-central/source/modules/libpref/init/StaticPrefList.yaml#8243

To verify the fix:

• Confirm each pref has no remaining users by searching its name on https://searchfox.org (only the definition should match).
• Build the tree (a full build is needed because StaticPrefList.yaml is code-generated):
  ./mach build

Tutorial to contribute:
https://firefox-source-docs.mozilla.org/contributing/contribution_quickref.html
https://firefox-source-docs.mozilla.org/contributing/stack_quickref.html

Please don't ask for the bug to be assigned. It will be automatically assigned to the first patch.

The following WebRender debug preferences are no longer in use. They are no longer in the GFX_WEBRENDER_DEBUG
flag table in gfx/thebes/gfxPlatform.cpp.

modules/libpref/init/all.js:
- gfx.webrender.debug.alpha-primitives
- gfx.webrender.debug.slow-frame-indicator

modules/libpref/init/StaticPrefList.yaml:
- gfx.webrender.debug.slow-cpu-frame-threshold

I believe this supersedes 2053563.

Also, I don't know if this is relevant, but I noticed that the following flags defined in gfx/thebes/gfxPlatform.cpp do not show up anywhere else when I search on https://searchfox.org:

• .smart-profiler
• .disable-opaque-pass
• .disable-alpha-pass
• .disable-clip-masks
• .restrict-blob-size

Backed out for causing bustage @ gfxPlatform.cpp

Backout link

Push with failures

Failure log

This is busted because gfx.webrender.debug.slow-cpu-frame-threshold is used in https://searchfox.org/firefox-main/source/gfx/thebes/gfxPlatform.cpp#569. Should I undo the change made to StaticPrefList.yaml?

Yes, I expected the code to build before being sent for review :)

FWIW that code is unnecessarily inefficient, should be just:

float threshold = StaticPrefs::...();

Apologies. I built in artifact mode. I'll do a full build before updating

https://hg.mozilla.org/mozilla-central/rev/2046d5147021

thanks