Add a TrustRegionStrategy::Summary object.

Change-Id: I7caee35a3408ee4a0ec16ba407410d822929340d
diff --git a/internal/ceres/trust_region_minimizer.cc b/internal/ceres/trust_region_minimizer.cc
index 476cc9d..19e3f35 100644
--- a/internal/ceres/trust_region_minimizer.cc
+++ b/internal/ceres/trust_region_minimizer.cc
@@ -250,7 +250,7 @@
     const time_t strategy_start_time = time(NULL);
     TrustRegionStrategy::PerSolveOptions per_solve_options;
     per_solve_options.eta = options_.eta;
-    LinearSolver::Summary strategy_summary =
+    TrustRegionStrategy::Summary strategy_summary =
         strategy->ComputeStep(per_solve_options,
                               jacobian,
                               residuals.data(),