[css-values-4][css-images-4][css-fonts-4] URL request modifiers (#8222)

Co-authored-by: Tab Atkins Jr. <jackalmage@gmail.com>

Author: noamr

css-fonts-4/Overview.bs

@@ -3254,7 +3254,7 @@ downloadable fonts to avoid large page reflows where possible.
 Font fetching requirements</h4>
 
 <div algorithm>
-	To <dfn>fetch a font</dfn> given a selected [=/url=] |url| for ''@font-face'' |rule|,
+	To <dfn>fetch a font</dfn> given a selected <<url>> |url| for ''@font-face'' |rule|,
 	[=fetch a style resource|fetch=] |url|,
 	with stylesheet being |rule|'s <a spec=cssom for=CSSRule>parent CSS style sheet</a>,
 	destination "font",

css-images-4/Overview.bs

@@ -140,7 +140,7 @@ Fetching External Images {#fetching-images}
 -------------------------------------------
 
 	To <dfn>fetch an external image for a stylesheet</dfn>,
-	given a [=/url=] |url| and {{CSSStyleSheet}} sheet,
+	given a <<url>> |url| and {{CSSStyleSheet}} sheet,
 	[=fetch a style resource=] given |url|,
 	with stylesheet {{CSSStyleSheet}},
 	destination "image",

css-values-4/Overview.bs

@@ -1069,46 +1069,79 @@ URL Modifiers</h4>
 URL Processing Model</h4>
 
 	<div algorithm>
-		To <dfn export>fetch a style resource</dfn> from [=/url=] |url|,
-		given a {{CSSStyleSheet}} |sheet|,
+		To <dfn export>fetch a style resource</dfn> from [=/url=] or
+		<<url>> |urlValue|, given a {{CSSStyleSheet}} |sheet|,
 		a string |destination| matching a {{RequestDestination}},
 		a "no-cors" or "cors" |corsMode|,
 		and an algorithm |processResponse| accepting a [=/response=] and a null, failure or byte
 		stream:
 
 		1. Let |environmentSettings| be |sheet|'s [=relevant settings object=].
 
-		3. Let |documentBase| be |environmentSettings|'s [=API base URL=].
+		2. Let |base| be |sheet|'s <a spec=cssom>stylesheet base URL</a> if it is not null, otherwise
+			|environmentSettings|'s [=API base URL=]. [[CSSOM]]
 
-		4. Let |base| be |sheet|'s <a spec=cssom>stylesheet base URL</a>. [[CSSOM]]
-
-		5. Let |referrer| be |documentBase|.
-
-		6. If |base| is null, set |base| to |documentBase|.
-
-		7. Let |parsedUrl| be the result of the [=URL parser=] steps with |url| and |base|.
+		3. Let |parsedUrl| be the result of the [=URL parser=] steps with |urlValue|'s [=/url=] and |base|.
 			If the algorithm returns an error, return.
 
-		8. If |corsMode| is "cors", set |referrer| to |sheet|'s
-			<a spec=cssom>location</a>. [[CSSOM]]
-
-		9. Let |req| be a new [=/request=] whose [=request/url=] is |parsedUrl|, whose
+		4. Let |req| be a new [=/request=] whose [=request/url=] is |parsedUrl|, whose
 			[=request/destination=] is |destination|, [=request/mode=] is |corsMode|,
 			[=request/origin=] is |environmentSettings|'s [=environment settings object/origin=],
 			[=request/credentials mode=] is "same-origin", [=request/use-url-credentials flag=] is
 			set, [=request/client=] is |environmentSettings|, and whose [=request/referrer=] is
-			|referrer|.
+			|environmentSettings|'s [=API base URL=].
+
+		5. [=Apply request modifiers from URL value=] given |req| and |urlValue|.
 
-		10. If |sheet|'s <a spec=cssom>origin-clean flag</a> is set, set |req|'s
-			[=request/initiator type=] to "css". [[CSSOM]]
+		6. If |req|'s [=request/mode=] is "cors",
+			set |req|'s [=request/referrer=] to |sheet|'s <a spec=cssom>location</a>. [[CSSOM]]
 
-		11. [=/Fetch|fetching=] |req|, with [=fetch/processresponseconsumebody=] set to
-			|processResponse|.
+		7. If |sheet|'s <a spec=cssom>origin-clean flag</a> is set,
+			set |req|'s [=request/initiator type=] to "css". [[CSSOM]]
+
+		8. [=/Fetch=] |req|,
+			with [=fetch/processresponseconsumebody=] set to |processResponse|.
 	</div>
 
-	Note: Resources loaded through CSS style sheets
-	are cached and cleared the same as any other resources
-	linked from the document.
+<h4 id='request-url-modifiers'>
+Request URL Modifiers</h4>
+
+	The <dfn><<request-url-modifier>></dfn>s represent <<url-modifier>>s 
+	that affect the resource's [=/request=]. 
+	Each <<request-url-modifier>> has a <dfn>request modifier steps</dfn> 
+	which accepts a [=/request=].
+
+	<pre class=prod>
+		<<request-url-modifier>> = <<crossorigin-modifier>> | <<integrity-modifier>> | <<referrerpolicy-modifier>>
+		<<crossorigin-modifier>> = crossorigin(anonymous | use-credentials)
+		<<integrity-modifier>> = integrity(<<string>>)
+		<<referrerpolicy-modifier>> = referrerpolicy(no-referrer | no-referrer-when-downgrade | same-origin | origin | strict-origin | origin-when-cross-origin | strict-origin-when-cross-origin | unsafe-url)
+	</pre>
+
+	<dl dfn-for="<<request-url-modifier>>">
+	<dt><dfn><<crossorigin-modifier>></dfn> = <dfn function lt="crossorigin()">crossorigin</dfn>(<dfn value>anonymous</dfn> | <dfn value>use-credentials</dfn>)
+	<dd>The [=request modifier steps=] for this modifier given [=/request=] |req| are:
+		1. Set [=/request=]'s [=request/mode=] to "cors".
+
+		2. If the given value is ''use-credentials'', set [=/request=]'s
+			[=request/credentials mode=] to "include".
+
+	<dt><dfn><<integrity-modifier>></dfn> = <dfn function lt="integrity()">integrity</dfn>(<<string>>)
+	<dd>The [=request modifier steps=] for this modifier given [=/request=] |req| are to set
+		[=/request=]'s [=request/integrity metadata=] to the given <<string>>.
+
+	<dt><dfn><<referrerpolicy-modifier>></dfn> = <dfn function lt="referrerpolicy()">referrerpolicy</dfn>(<dfn value>no-referrer</dfn> | <dfn value>no-referrer-when-downgrade</dfn> | <dfn value>same-origin</dfn> | <dfn value>origin</dfn> | <dfn value>strict-origin</dfn> | <dfn value>origin-when-cross-origin</dfn> | <dfn value>strict-origin-when-cross-origin</dfn> | <dfn value>unsafe-url</dfn>)
+	<dd>The [=request modifier steps=] for this modifier given [=/request=] |req| are to set
+		[=/request=]'s [=request/referrer policy=] to the {{ReferrerPolicy}} that matches the given value.
+	</dl>
+
+	<div algorithm>
+		To <dfn>apply request modifiers from URL value</dfn>
+		given a [=/request=] |req| 
+		and a <<url>> |url|,
+		call the [=request modifier steps=] for |url|'s <<request-url-modifier>>s in sequence
+		given |req|.
+	</div>
 
 <h2 id="numeric-types">
 Numeric Data Types</h2>