[Storage] Normalize storage partition path before garbage collection

content/browser/storage_partition_impl_map.cc

Index: content/browser/storage_partition_impl_map.cc
diff --git a/content/browser/storage_partition_impl_map.cc b/content/browser/storage_partition_impl_map.cc
index 74a212f2d1b9b1581e49fda4df51c578caeec3be..fdfb34e3ebd5ba873d25fecaabf910ad208cc174 100644
--- a/content/browser/storage_partition_impl_map.cc
+++ b/content/browser/storage_partition_impl_map.cc
@@ -266,6 +266,27 @@ void BlockingObliteratePath(
   }
 }
 
+// Ensures each path in |active_paths| is a direct child of storage_root.
+void NormalizeActivePaths(const base::FilePath& storage_root,
+                          base::hash_set<base::FilePath>* active_paths) {
+  base::hash_set<base::FilePath> normalized_active_paths;
+
+  for (base::hash_set<base::FilePath>::iterator iter = active_paths->begin();
+       iter != active_paths->end(); ++iter) {
+    base::FilePath relative_path;
+    if (!storage_root.AppendRelativePath(*iter, &relative_path))
+      continue;
+
+    std::vector<base::FilePath::StringType> components;
+    relative_path.GetComponents(&components);
+
+    DCHECK(!relative_path.empty());
+    normalized_active_paths.insert(storage_root.Append(components.front()));
+  }
+
+  active_paths->swap(normalized_active_paths);
+}
+
 // Deletes all entries inside the |storage_root| that are not in the
 // |active_paths|.  Deletion is done in 2 steps:
 //
@@ -289,6 +310,8 @@ void BlockingGarbageCollect(
     scoped_ptr<base::hash_set<base::FilePath> > active_paths) {
   CHECK(storage_root.IsAbsolute());
 
+  NormalizeActivePaths(storage_root, active_paths.get());
+
   base::FileEnumerator enumerator(storage_root, false, kAllFileTypes);
   base::FilePath trash_directory;
   if (!base::CreateTemporaryDirInDir(storage_root, kTrashDirname,