[USS] Move GetAllNodes from backend to controller

components/sync/driver/glue/sync_backend_host_mock.cc

Index: components/sync/driver/glue/sync_backend_host_mock.cc
diff --git a/components/sync/driver/glue/sync_backend_host_mock.cc b/components/sync/driver/glue/sync_backend_host_mock.cc
index 7a978ff8455a13b2ab6b3cb31b1b32e463f283e3..7a8b65485a02f19bfd9c3d60b1f9a7320d3a2a97 100644
--- a/components/sync/driver/glue/sync_backend_host_mock.cc
+++ b/components/sync/driver/glue/sync_backend_host_mock.cc
@@ -137,12 +137,6 @@ void SyncBackendHostMock::EnableDirectoryTypeDebugInfoForwarding() {}
 
 void SyncBackendHostMock::DisableDirectoryTypeDebugInfoForwarding() {}
 
-void SyncBackendHostMock::GetAllNodesForTypes(
-    syncer::ModelTypeSet types,
-    base::Callback<void(const std::vector<syncer::ModelType>& type,
-                        std::vector<std::unique_ptr<base::ListValue>>)>
-        callback) {}
-
 void SyncBackendHostMock::set_fail_initial_download(bool should_fail) {
   fail_initial_download_ = should_fail;
 }