Auto merge of #20431 - talklittle:issues-13234-5600-squashed, r=jdm

TextDecoder: streaming decode, ignoreBOM

<!-- Please describe your changes on the following line: -->
Implement streaming decode and ignoreBOM flag for TextDecoder.

https://encoding.spec.whatwg.org/#dom-textdecoder-decode

https://encoding.spec.whatwg.org/#dom-textdecoder-ignorebom

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #13234 (github issue number if applicable).
- [x] These changes fix #5600 (github issue number if applicable).

<!-- Either: -->
- [ ] There are tests for these changes OR
- [x] These changes do not require tests because the wpt tests are used for testing:

* /encoding/textdecoder-fatal-streaming.html
* /encoding/textdecoder-streaming.html
* /encoding/textdecoder-ignorebom.html

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1 files changed, 4 insertions, 1 deletions

diff --git a/components/script/dom/bindings/trace.rs b/components/script/dom/bindings/trace.rs
index be38b14a540..0fd94953e3b 100644
--- a/components/script/dom/bindings/trace.rs
+++ b/components/script/dom/bindings/trace.rs
@@ -47,7 +47,7 @@ use dom::bindings::root::{Dom, DomRoot};
 use dom::bindings::str::{DOMString, USVString};
 use dom::bindings::utils::WindowProxyHandler;
 use dom::document::PendingRestyle;
-use encoding_rs::Encoding;
+use encoding_rs::{Decoder, Encoding};
 use euclid::{Transform2D, Transform3D, Point2D, Vector2D, Rect, TypedSize2D, TypedScale};
 use euclid::Length as EuclidLength;
 use html5ever::{Prefix, LocalName, Namespace, QualName};
@@ -127,6 +127,9 @@ unsafe_no_jsmanaged_fields!(CSSError);
 
 unsafe_no_jsmanaged_fields!(&'static Encoding);
 
+unsafe_no_jsmanaged_fields!(RefCell<Decoder>);
+unsafe_no_jsmanaged_fields!(RefCell<Vec<u8>>);
+
 unsafe_no_jsmanaged_fields!(Reflector);
 
 unsafe_no_jsmanaged_fields!(Duration);