Add export to terms needed by URL spec.

Also update "Origin of blob URLs" section since the algorithm that was
there will be part of the URL spec instead.

Part of the work to address #63

Author: mkruisselbrink

index.bs

@@ -1620,10 +1620,10 @@ A [=blob URL store=] is a [=map=]
 where [=map/keys=] are [=valid URL strings=]
 and [=map/values=] are [=blob URL Entries=].
 
-A blob URL entry consists of
-an object (typically a {{Blob}},
+A  export>blob URL entry consists of
+an export for="blob URL entry">object (typically a {{Blob}},
 but other specs can extend this to refer to other types of objects),
-and an environment (an [=environment settings object=]).
+and an export for="blob URL entry">environment (an [=environment settings object=]).
 
 [=map/Keys=] in the [=blob URL store=] (also known as blob URLs)
 are [=valid URL strings=] that when [=URL parser|parsed=]
@@ -1689,33 +1689,22 @@ To resolve a blob URL given a |url
 
 
 
-Futher requirements for the parsing an fetching model for [=blob URLs=] are defined in the [[!URL]] and [[!Fetch]] specifications.
+Futher requirements for the parsing and fetching model for [=blob URLs=] are defined in the [[!URL]] and [[!Fetch]] specifications.
 
 
 Origin of blob URLs
 
-
-To resolve the origin of a blob URL given a |url| (a [=URL=]), run the following steps:
+*This section is informative.*
 
-1. [=Assert=]: |url|'s [=url/scheme=] is "`blob`".
-1. Let |entry| be the result of [=blob URL/resolve|resolving=] |url|.
-1. If |entry| is not failure, return |entry|'s [=blob URL entry/environment=]'s [=environment settings object/origin=].
-1. Let |nested url| be the result of [=URL parser|parsing=] |url|'s [=url/path=][0].
-1. Return a new [=opaque origin=], if |nested url| is failure, and |nested url|'s [=url/origin=] otherwise.
+The origin of a blob URL is always the same as that of the environment that created the URL,
+as long as the URL hasn't been revoked yet. This is achieved by the [[URL]] spec looking up
+the URL in the [=blob URL store=] when parsing a URL, and using that entry to return
+the correct origin.
 
-
-
-Note: The effect of this algorithm is that the origin of a blob URL is always
-the same as that of the environment that created the URL,
-as long as the URL hasn't been revoked yet.
 If the URL was revoked the serialization of the origin will still remain the same
 as the serialization of the origin of the environment that created the blob URL,
-but for opaque origins the origin itself might be distinct.
-This difference isn't observable though, since a revoked blob URL can't be resolved/fetched anymore anyway.
-
-Issue: The [[URL]] spec should be updated to refer to this algorithm to resolve the origin of a blob URL when the URL is first parsed.
-This is tracked in issue #63 and in
-whatwg/url#127.
+but for opaque origins the origin itself might be distinct. This difference isn't
+observable though, since a revoked blob URL can't be resolved/fetched anymore anyway.
 
 
 Lifetime of blob URLs
@@ -1756,7 +1745,7 @@ The revokeObjectURL(|url|) st
 
 1. Let |url record| be the result of [=URL parser|parsing=] |url|.
 1. If |url record|'s [=url/scheme=] is not "`blob`", return.
-1. Let |origin| be the result of [=resolving the origin=] of |url record|.
+1. Let |origin| be the [=url/origin=] of |url record|.
 1. Let |settings| be the [=current settings object=].
 1. If |origin| is not [=same origin=] with |settings|'s [=environment settings object/origin=], return.
 1. [=Remove an entry from the Blob URL Store=] for |url|.