DOMStorageContextImpl that's implemented in terms of the new dom_storage classes.

webkit/dom_storage/dom_storage_area.cc

Index: webkit/dom_storage/dom_storage_area.cc
===================================================================
--- webkit/dom_storage/dom_storage_area.cc	(revision 127221)
+++ webkit/dom_storage/dom_storage_area.cc	(working copy)
@@ -16,6 +16,17 @@
 
 namespace dom_storage {
 
+// static
+const FilePath::CharType DomStorageArea::kDatabaseFileExtension[] =
+    FILE_PATH_LITERAL("localstorage");
+
+// static
+FilePath DomStorageArea::DatabaseFileNameFromOrigin(const GURL& origin) {
+  std::string filename = fileapi::GetOriginIdentifierFromURL(origin);
+  return FilePath().AppendASCII(filename).ReplaceExtension(

[michaeln, 2012/03/19 00:36:29]

Fun with FilePaths... there is no method to AddExtension afaict, this usage of
ReplaceExtension is destructive since the 'origin_id' string format includes '.'
characters which look like filename extensions. So of course... you start with
just the extension as the filename, and then InsertBefore it the filename. Makes
perfect sense.

+      kDatabaseFileExtension);
+}
+
 DomStorageArea::DomStorageArea(
     int64 namespace_id, const GURL& origin,
     const FilePath& directory, DomStorageTaskRunner* task_runner)
@@ -164,11 +175,4 @@
   commit_in_flight_ = false;
 }
 
-// static
-FilePath DomStorageArea::DatabaseFileNameFromOrigin(const GURL& origin) {
-  std::string filename = fileapi::GetOriginIdentifierFromURL(origin)
-      + ".localstorage";
-  return FilePath().AppendASCII(filename);
-}
-
 }  // namespace dom_storage