Pass args to SyncManager::Init via a struct.

sync/internal_api/public/test/fake_sync_manager.h

Index: sync/internal_api/public/test/fake_sync_manager.h
diff --git a/sync/internal_api/public/test/fake_sync_manager.h b/sync/internal_api/public/test/fake_sync_manager.h
index 3fb2a7a1b4cc65d2ca1335fcbfa782b0edf0cfa9..c8f9f83686f684150b20c3449f3a77132e8d5ebf 100644
--- a/sync/internal_api/public/test/fake_sync_manager.h
+++ b/sync/internal_api/public/test/fake_sync_manager.h
@@ -77,23 +77,7 @@ class FakeSyncManager : public SyncManager {
   // SyncManager implementation.
   // Note: we treat whatever message loop this is called from as the sync
   // loop for purposes of callbacks.
-  virtual void Init(
-      const base::FilePath& database_location,
-      const WeakHandle<JsEventHandler>& event_handler,
-      const GURL& service_url,
-      scoped_ptr<HttpPostProviderFactory> post_factory,
-      const std::vector<scoped_refptr<ModelSafeWorker> >& workers,
-      ExtensionsActivity* extensions_activity,
-      ChangeDelegate* change_delegate,
-      const SyncCredentials& credentials,
-      const std::string& invalidator_client_id,
-      const std::string& restored_key_for_bootstrapping,
-      const std::string& restored_keystore_key_for_bootstrapping,
-      InternalComponentsFactory* internal_components_factory,
-      Encryptor* encryptor,
-      scoped_ptr<UnrecoverableErrorHandler> unrecoverable_error_handler,
-      ReportUnrecoverableErrorFunction report_unrecoverable_error_function,
-      CancelationSignal* cancelation_signal) OVERRIDE;
+  virtual void Init(InitArgs* args) OVERRIDE;
   virtual ModelTypeSet InitialSyncEndedTypes() OVERRIDE;
   virtual ModelTypeSet GetTypesWithEmptyProgressMarkerToken(
       ModelTypeSet types) OVERRIDE;