Componentize FakeSigninManager and SigninManager prefs

components/signin/core/browser/signin_manager_base.h

Index: components/signin/core/browser/signin_manager_base.h
diff --git a/components/signin/core/browser/signin_manager_base.h b/components/signin/core/browser/signin_manager_base.h
index fb712ad408a2f2f87d77e15ff63aa25e38cd2616..ff7364f3c700e2811e585aac11cb3a6a2e772979 100644
--- a/components/signin/core/browser/signin_manager_base.h
+++ b/components/signin/core/browser/signin_manager_base.h
@@ -37,9 +37,14 @@
 #include "google_apis/gaia/google_service_auth_error.h"
 
 class AccountTrackerService;
+class PrefRegistrySimple;
 class PrefService;
 class SigninClient;
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 class SigninManagerBase : public KeyedService {
  public:
   class Observer {
@@ -64,6 +69,12 @@ class SigninManagerBase : public KeyedService {
                     AccountTrackerService* account_tracker_service);
   ~SigninManagerBase() override;
 
+  // Registers per-profile prefs.
+  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
+
+  // Registers per-install prefs.
+  static void RegisterPrefs(PrefRegistrySimple* registry);
+
   // If user was signed in, load tokens from DB if available.
   virtual void Initialize(PrefService* local_state);
   bool IsInitialized() const;