Implement Blob.close().

Source/core/dom/DOMURL.cpp

Index: Source/core/dom/DOMURL.cpp
diff --git a/Source/core/dom/DOMURL.cpp b/Source/core/dom/DOMURL.cpp
index 8881223f72445c4d4933110e6246154d56d8229f..f3ce017bebe6865f9fe2d1189f34c6cb9a997929 100644
--- a/Source/core/dom/DOMURL.cpp
+++ b/Source/core/dom/DOMURL.cpp
@@ -67,16 +67,16 @@ String DOMURL::createObjectURL(ExecutionContext* executionContext, Blob* blob)
 {
     if (!executionContext || !blob)
         return String();
-    return createPublicURL(executionContext, blob);
+    return createPublicURL(executionContext, blob, blob->uuid());
 }
 
-String DOMURL::createPublicURL(ExecutionContext* executionContext, URLRegistrable* registrable)
+String DOMURL::createPublicURL(ExecutionContext* executionContext, URLRegistrable* registrable, const String& uuid)

[michaeln, 2014/02/12 20:33:04]

Not sure we need the addition of the uuid? The balancing call to revoke all for
a registrable object could use the URLRegistrable* value as the key. Not all
registerable object types have seperate string uuids associated with them, if
the ptr value can serve as the key, they too can be revoked.

Any reason to not use the ptr value as the key? I guess internal data structs
should view the key as a void* since URLRegistrations can outlive the Blob
object.

API'wise, it might be nice to provide a balancing method to revoke all for a
registerable defined on this DOMURL class since this is where they're created.

[sof, 2014/02/12 22:28:26]

I like the idea of using the URLRegistrable* as the unique value, will have to
think about it overnight.

There are some issues though -- when the Blobs become objects on the Oilpan
heap, you suddenly have to contend with references to GCed objects. And you have
to retire/disable a URLRegistrable* once it becomes garbage..as you don't want
to run the risk of having false matches when you do close() a Blob & pass along
its pointer value. i.e., the same pointer value could have belonged to an
earlier Blob...and you're not allowed to revoke URLs upon their associated Blob
being garbage collected.

[michaeln, 2014/02/12 22:34:11]

Right, that's sounds like a very good reason to not use the ptr value as the
key.

 {
     KURL publicURL = BlobURL::createPublicURL(executionContext->securityOrigin());
     if (publicURL.isEmpty())
         return String();
 
-    executionContext->publicURLManager().registerURL(executionContext->securityOrigin(), publicURL, registrable);
+    executionContext->publicURLManager().registerURL(executionContext->securityOrigin(), publicURL, registrable, uuid);
 
     return publicURL.string();
 }