Web updates

Streams cf19e8dd1309

Editorial: use structs instead of records Closes #670. The main advantage here is that it lets us define the structs and their items in more detail, so that the reader has a better chance of knowing what they mean. Additionally, we can easily cross-link to the item definitions from their usage sites. It also has the minor advantage of moving us more toward other web specifications, and reducing the problem posed by #825. This includes the following changes that go beyond a fancy search-and-replace: * Instead of representing a writable stream's internal queue as containing chunks that were either the string "close" or a Record{ [[chunk]]: jsValue }}, we use a "close sentinel" value which can be used alongside the chunks directly. * The "ctor" record field in the pending pull-into descriptors is renamed to "view constructor".

Domenic Denicola

HTML 70b8bb4e8bbd

Add cross-origin embedder policy Merges into HTML. Associated PRs: * * * Fixes #5368, fixes #5634, fixes, and fixes Follow-up: #4916, #4919, #4930 #5223, and #5391. (As well as defining cross-origin isolated, per #4732.)

Yutaka Hirano