Fix locking order in render_pipeline_get_bind_group_layout

[nical]

Checklist

• Run cargo clippy.

Connections

Blocks https://bugzilla.mozilla.org/show_bug.cgi?id=1856371

Description

The code path for when IDs are provided externally was creating a new root token while the previous one still existed. The right thing to do is to ensure the other guards are closed before assigning the newly created bind group which this patch does by scoping the them.

Also add the equivalent code for compute_pipeline_get_bind_group_layout.

Testing

This is covered by the CTS in Firefox.

[jimblandy]

@nical There are checks in Token::root that are supposed to detect attempts to create multiple roots simultaneously on the same thread. Did those debug assertions trigger in this case?

[cwfitzgerald]

(These checks probably should be bounded by "strict-asserts" rather than debug_assertions)

[jimblandy]

Looks good to me.

[jimblandy]

(These checks probably should be bounded by "strict-asserts" rather than debug_assertions)

Oooh, good point.

[jimblandy]

(These checks probably should be bounded by "strict-asserts" rather than debug_assertions)

Filed as #4258.

[nical]

@nical There are checks in Token::root that are supposed to detect attempts to create multiple roots simultaneously on the same thread. Did those debug assertions trigger in this case?

Yes that's how I found the issue.