Introduce CertErrors::ToDebugString().

net/cert/internal/cert_errors.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // ----------------------------
 // Overview of error design
 // ----------------------------
 //
 // Certificate path validation may emit a sequence of errors/warnings. These
 // are represented by |CertErrors|.
@@ skipping 97 matching lines @@
   void AddWithParam(CertErrorType type,
                     std::unique_ptr<CertErrorParams> params);
 
   void AddWith1DerParam(CertErrorType type, const der::Input& der1);
   void AddWith2DerParams(CertErrorType type,
                          const der::Input& der1,
                          const der::Input& der2);
 
   const std::vector<CertError>& errors() const { return errors_; }
 
+  // Dumps a textual representation of the errors for debugging purposes.
+  std::string ToDebugString() const;
+
  private:
   std::vector<CertError> errors_;
 
   DISALLOW_COPY_AND_ASSIGN(CertErrors);
 };
 
 // --------------------------
 // Context scopers
 // --------------------------
 
@@ skipping 45 matching lines @@
  private:
   const std::string der1_;
   const std::string der2_;
 
   DISALLOW_COPY_AND_ASSIGN(CertErrorParamsDer2);
 };
 
 }  // namespace net
 
 #endif  // NET_CERT_INTERNAL_CERT_ERRORS_H_