Covariance estimation using SuiteSparseQR.

Change-Id: I70d1686e3288fdde5f9723e832e15ffb857d6d85
diff --git a/internal/ceres/covariance_impl.h b/internal/ceres/covariance_impl.h
index 0be53e7..0e7e217 100644
--- a/internal/ceres/covariance_impl.h
+++ b/internal/ceres/covariance_impl.h
@@ -64,8 +64,9 @@
       ProblemImpl* problem);
 
   bool ComputeCovarianceValues();
-  bool ComputeCovarianceValuesUsingSuiteSparse();
-  bool ComputeCovarianceValuesUsingEigen();
+  bool ComputeCovarianceValuesUsingSparseCholesky();
+  bool ComputeCovarianceValuesUsingSparseQR();
+  bool ComputeCovarianceValuesUsingDenseSVD();
 
   const CompressedRowSparseMatrix* covariance_matrix() const {
     return covariance_matrix_.get();
@@ -80,9 +81,6 @@
   map<const double*, int> parameter_block_to_row_index_;
   set<const double*> constant_parameter_blocks_;
   scoped_ptr<CompressedRowSparseMatrix> covariance_matrix_;
-#ifndef CERES_NO_SUITESPARSE
-  SuiteSparse ss_;
-#endif
 };
 
 }  // namespace internal