Prepare to abstract PersistedData by making it part of the configurator.

components/update_client/configurator.h

Index: components/update_client/configurator.h
diff --git a/components/update_client/configurator.h b/components/update_client/configurator.h
index be2caff58d870274f40463d99995f94dc01e990b..9fca17a3b0f3a4b945a505ca57859c7625f6cc34 100644
--- a/components/update_client/configurator.h
+++ b/components/update_client/configurator.h
@@ -26,6 +26,7 @@ class URLRequestContextGetter;
 namespace update_client {
 
 class OutOfProcessPatcher;
+class PersistedData;
 
 // Controls the component updater behavior.
 // TODO(sorin): this class will be split soon in two. One class controls
@@ -120,19 +121,18 @@ class Configurator : public base::RefCountedThreadSafe<Configurator> {
   virtual scoped_refptr<base::SequencedTaskRunner> GetSequencedTaskRunner()
       const = 0;
 
-  // Returns a PrefService that the update_client can use to store persistent
-  // update information. The PrefService must outlive the entire update_client,
-  // and be safe to access from the thread the update_client is constructed
-  // on.
-  // Returning null is safe and will disable any functionality that requires
-  // persistent storage.
-  virtual PrefService* GetPrefService() const = 0;
-
   // Returns true if the Chrome is installed for the current user only, or false
   // if Chrome is installed for all users on the machine. This function must be
   // called only from a blocking pool thread, as it may access the file system.
   virtual bool IsPerUserInstall() const = 0;
 
+  // Returns a PersistedData object that update_client can use to store
+  // persistent update information. This persisted data depends on a
+  // PrefService, which must outlive the entire update_client.
+  // When this PrefService is null, any functionality requaring persistent
+  // storage will be disabled.
+  virtual std::unique_ptr<PersistedData> CreateMetadata() const = 0;
+
  protected:
   friend class base::RefCountedThreadSafe<Configurator>;