Convert TrackedPreferenceValidationDelegate into a mojo interface.

chrome/browser/safe_browsing/services_delegate_stub.cc

Index: chrome/browser/safe_browsing/services_delegate_stub.cc
diff --git a/chrome/browser/safe_browsing/services_delegate_stub.cc b/chrome/browser/safe_browsing/services_delegate_stub.cc
index 337c5aa48fa6010a1b532a8fba136a4de15e3012..b3f189d161191f42670677bf557a21c0e6a2d7ed 100644
--- a/chrome/browser/safe_browsing/services_delegate_stub.cc
+++ b/chrome/browser/safe_browsing/services_delegate_stub.cc
@@ -7,6 +7,7 @@
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "components/safe_browsing_db/v4_local_database_manager.h"
+#include "services/preferences/public/interfaces/tracked_preference_validation_delegate.mojom.h"
 
 namespace safe_browsing {
 
@@ -45,9 +46,9 @@ void ServicesDelegateStub::RefreshState(bool enable) {}
 void ServicesDelegateStub::ProcessResourceRequest(
     const ResourceRequestInfo* request) {}
 
-std::unique_ptr<TrackedPreferenceValidationDelegate>
+std::unique_ptr<prefs::mojom::TrackedPreferenceValidationDelegate>
 ServicesDelegateStub::CreatePreferenceValidationDelegate(Profile* profile) {
-  return std::unique_ptr<TrackedPreferenceValidationDelegate>();
+  return nullptr;
 }
 
 void ServicesDelegateStub::RegisterDelayedAnalysisCallback(