Make the match algorithm accept the URL struct

In w3c/ServiceWorker#1701, the ServiceWorker static routing API uses the match algorithm to match the request URL. However, the original match algorithm accepts a URLPatternInput object, and it does not accept a URL struct. To allow the ServiceWorker static routing API to use the match algorithm, we need to make the match algorithm to accept the URL struct.

Fixes: #218.

spec.bs

@@ -468,7 +468,7 @@ A <dfn>component</dfn> is a [=struct=] with the following [=struct/items=]:
 </div>
 
 <div algorithm>
-  To perform a <dfn export for="URL pattern">match</dfn> given a [=URL pattern=] |urlPattern|, a {{URLPatternInput}} |input|, and an optional string |baseURLString|:
+  To perform a <dfn export for="URL pattern">match</dfn> given a [=URL pattern=] |urlPattern|, a {{URLPatternInput}} or [=/URL=] |input|, and an optional string |baseURLString|:
 
   1. Let |protocol| be the empty string.
   1. Let |username| be the empty string.
@@ -492,13 +492,16 @@ A <dfn>component</dfn> is a [=struct=] with the following [=struct/items=]:
     1. Set |search| to |applyResult|["{{URLPatternInit/search}}"].
     1. Set |hash| to |applyResult|["{{URLPatternInit/hash}}"].
   1. Otherwise:
-    1. Let |baseURL| be null.
-    1. If |baseURLString| was given, then:
-      1. Set |baseURL| to the result of [=URL parser|parsing=] |baseURLString|.
-      1. If |baseURL| is failure, return null.
-      1. [=list/Append=] |baseURLString| to |inputs|.
-    1. Let |url| be the result of [=URL parser|parsing=] |input| given |baseURL|.
-    1. If |url| is failure, return null.
+    1. Let |url| be |input|.
+    1. If |input| is a {{USVString}}:
+      1. Let |baseURL| be null.
+      1. If |baseURLString| was given, then:
+        1. Set |baseURL| to the result of [=URL parser|parsing=] |baseURLString|.
+        1. If |baseURL| is failure, return null.
+        1. [=list/Append=] |baseURLString| to |inputs|.
+      1. Set |url| to the result of [=URL parser|parsing=] |input| given |baseURL|.
+      1. If |url| is failure, return null.
+    1. [=Assert=]: |url| is a [=/URL=].
     1. Set |protocol| to |url|'s [=url/scheme=].
     1. Set |username| to |url|'s [=url/username=].
     1. Set |password| to |url|'s [=url/password=].