Pass document's settings object when processing a manifest

[marcoscaceres]

Pass document's relevant settings object when processing a manifest

The Web App Manifest spec's "processing a manifest" algorithm now accepts an optional environment settings object (client) parameter, used to set the request client when fetching manifest image resources. This enables CSP and service worker interception for those fetches.

This PR passes the link element's node document's relevant settings object as the client parameter when invoking "process the manifest".

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• At least two implementers are interested (and none opposed):
  • Chromium (already fetches through document frame via DownloadImageInFrame())
  • Gecko (already fetches via window.fetch() through content window with mode: "cors")
• Tests are written and can be reviewed and commented upon at:
  • No observable behavior change for this PR alone (wires up a parameter). Tests for the end-to-end behavior (CSP applying to manifest icon fetches) tracked in w3c/manifest#1171.
• Implementation bugs are filed:
  • Chromium: already conformant
  • Gecko: already conformant
  • WebKit: Bug 311872
  • Deno
  • Node.js
• Corresponding HTML AAM & ARIA in HTML issues & PRs — N/A
• MDN issue is filed — N/A, no developer-facing change
• The top of this comment includes a clear commit message to use.

Context

• w3c/manifest#1171 — adds client parameter to "processing a manifest" and defines "fetch a manifest image resource" algorithm
• w3c/image-resource#50 — sets fetch mode to cors in "fetching an image resource"
• WebKit Bug 311872 — tracks WebKit implementation

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/links.html ( diff )

[marcoscaceres]

@dmurph, do you want to check this too from the Chromium side?