Switch to mojo localstorage backend by default.

content/browser/dom_storage/local_storage_context_mojo.h

Index: content/browser/dom_storage/local_storage_context_mojo.h
diff --git a/content/browser/dom_storage/local_storage_context_mojo.h b/content/browser/dom_storage/local_storage_context_mojo.h
index 342fe0a9e619688664465a2ae4e10b172bc4aa24..a977a9f57e615dcb143bb0264d6fd039b0c2dd9b 100644
--- a/content/browser/dom_storage/local_storage_context_mojo.h
+++ b/content/browser/dom_storage/local_storage_context_mojo.h
@@ -28,8 +28,8 @@ class DOMStorageTaskRunner;
 class LevelDBWrapperImpl;
 struct LocalStorageUsageInfo;
 
-// Used for mojo-based LocalStorage implementation (behind --mojo-local-storage
-// for now).
+// Used for mojo-based LocalStorage implementation (can be disabled with
+// --disable-mojo-local-storage for now).
 // Created on the UI thread, but all further methods are called on the IO
 // thread. Furthermore since destruction of this class can involve asynchronous
 // steps, it can only be deleted by calling ShutdownAndDelete (on the IO