Select a more appropiate appcache based on the opener or the parent of the new document.

webkit/appcache/appcache_request_handler.cc

Index: webkit/appcache/appcache_request_handler.cc
===================================================================
--- webkit/appcache/appcache_request_handler.cc	(revision 81647)
+++ webkit/appcache/appcache_request_handler.cc	(working copy)
@@ -188,11 +188,19 @@
 
 void AppCacheRequestHandler::MaybeLoadMainResource(net::URLRequest* request) {
   DCHECK(!job_);
+  DCHECK(host_);
 
+  const AppCacheHost* spawning_host =
+      ResourceType::IsSharedWorker(resource_type_) ?
+          host_ : host_->GetSpawningHost();
+  GURL preferred_manifest_url = spawning_host ?
+      spawning_host->preferred_manifest_url() : GURL();
+
   // We may have to wait for our storage query to complete, but
   // this query can also complete syncrhonously.
   job_ = new AppCacheURLRequestJob(request, storage());
-  storage()->FindResponseForMainRequest(request->url(), this);
+  storage()->FindResponseForMainRequest(
+      request->url(), preferred_manifest_url, this);
 }
 
 void AppCacheRequestHandler::OnMainResponseFound(
@@ -216,6 +224,7 @@
       // in advance of subresource loads happening, secondly to prevent the
       // AppCache from falling out of the working set on frame navigations.
       host_->LoadMainResourceCache(cache_id);
+      host_->set_preferred_manifest_url(manifest_url);
     }
   } else {
     DCHECK(ResourceType::IsSharedWorker(resource_type_));