From FilePath::AppendAndResolveRelative() to file_util::AbsolutePath().

chrome/common/extensions/extension_resource.cc

Index: chrome/common/extensions/extension_resource.cc
===================================================================
--- chrome/common/extensions/extension_resource.cc	(revision 30093)
+++ chrome/common/extensions/extension_resource.cc	(working copy)
@@ -40,22 +40,26 @@
   std::vector<FilePath> l10n_relative_paths;
   extension_l10n_util::GetL10nRelativePaths(relative_path,
                                             &l10n_relative_paths);
+  // We need to resolve the parent references in the extension_root
+  // path on its own because IsParent doesn't like parent references.
+  FilePath clean_extension_root(extension_root);
+  if (!file_util::AbsolutePath(&clean_extension_root))
+    return FilePath();
 
   // Stat l10n file(s), and return new path if it exists.
   for (size_t i = 0; i < l10n_relative_paths.size(); ++i) {
-    FilePath full_path;
-    if (extension_root.AppendAndResolveRelative(l10n_relative_paths[i],
-                                                &full_path) &&
-        extension_root.IsParent(full_path) &&
+    FilePath full_path = clean_extension_root.Append(l10n_relative_paths[i]);
+    if (file_util::AbsolutePath(&full_path) &&
+        clean_extension_root.IsParent(full_path) &&
         file_util::PathExists(full_path)) {
       return full_path;
     }
   }
 
   // Fall back to root resource.
-  FilePath full_path;
-  if (extension_root.AppendAndResolveRelative(relative_path, &full_path) &&
-      extension_root.IsParent(full_path)) {
+  FilePath full_path = clean_extension_root.Append(relative_path);
+  if (file_util::AbsolutePath(&full_path) &&
+      clean_extension_root.IsParent(full_path)) {
     return full_path;
   }