DevTools: Do not treat saved path as dot separated keys when saving file systems.

chrome/browser/devtools/devtools_file_helper.cc

Index: chrome/browser/devtools/devtools_file_helper.cc
diff --git a/chrome/browser/devtools/devtools_file_helper.cc b/chrome/browser/devtools/devtools_file_helper.cc
index fe7277cceb605f8253fb02f8d3dd9575b549a2fb..d715ff2b4c14eab75a6e2cd92cb1dad8049283c0 100644
--- a/chrome/browser/devtools/devtools_file_helper.cc
+++ b/chrome/browser/devtools/devtools_file_helper.cc
@@ -318,7 +318,8 @@ void DevToolsFileHelper::AddUserConfirmedFileSystem(
   DictionaryPrefUpdate update(profile_->GetPrefs(),
                               prefs::kDevToolsFileSystemPaths);
   DictionaryValue* file_systems_paths_value = update.Get();
-  file_systems_paths_value->Set(file_system_path, Value::CreateNullValue());
+  file_systems_paths_value->SetWithoutPathExpansion(file_system_path,
+                                                    Value::CreateNullValue());
 
   FileSystem filesystem = CreateFileSystemStruct(web_contents_,
                                                  file_system_id,