Use stricter type checking in UMA_HISTOGRAM_ENUMERATION

net/ssl/ssl_connection_status_flags.h

 // Copyright (c) 2012 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.
 
 #ifndef NET_SSL_SSL_CONNECTION_STATUS_FLAGS_H_
 #define NET_SSL_SSL_CONNECTION_STATUS_FLAGS_H_
 
 #include <stdint.h>
 
 #include "base/logging.h"
@@ skipping 17 matching lines @@
   SSL_CONNECTION_VERSION_SHIFT = 20,
   SSL_CONNECTION_VERSION_MASK = 7,
 
   // 1 << 31 (the sign bit) is reserved so that the SSL connection status will
   // never be negative.
 };
 
 // NOTE: the SSL version enum constants must be between 0 and
 // SSL_CONNECTION_VERSION_MASK, inclusive. These values are persisted to disk
 // and used in UMA, so they must remain stable.
-enum {
+enum SSLVersion {
   SSL_CONNECTION_VERSION_UNKNOWN = 0,  // Unknown SSL version.
   SSL_CONNECTION_VERSION_SSL2 = 1,
   SSL_CONNECTION_VERSION_SSL3 = 2,
   SSL_CONNECTION_VERSION_TLS1 = 3,
   SSL_CONNECTION_VERSION_TLS1_1 = 4,
   SSL_CONNECTION_VERSION_TLS1_2 = 5,
   SSL_CONNECTION_VERSION_TLS1_3 = 6,
   SSL_CONNECTION_VERSION_QUIC = 7,
   SSL_CONNECTION_VERSION_MAX,
 };
 static_assert(SSL_CONNECTION_VERSION_MAX - 1 <= SSL_CONNECTION_VERSION_MASK,
               "SSL_CONNECTION_VERSION_MASK too small");
 
 inline uint16_t SSLConnectionStatusToCipherSuite(int connection_status) {
   return static_cast<uint16_t>(connection_status);
 }
 
-inline int SSLConnectionStatusToVersion(int connection_status) {
-  return (connection_status >> SSL_CONNECTION_VERSION_SHIFT) &
-         SSL_CONNECTION_VERSION_MASK;
+inline SSLVersion SSLConnectionStatusToVersion(int connection_status) {
+  return static_cast<SSLVersion>(
+      (connection_status >> SSL_CONNECTION_VERSION_SHIFT) &
+      SSL_CONNECTION_VERSION_MASK);
 }
 
 inline void SSLConnectionStatusSetCipherSuite(uint16_t cipher_suite,
                                               int* connection_status) {
   // Clear out the old ciphersuite.
   *connection_status &= ~SSL_CONNECTION_CIPHERSUITE_MASK;
   // Set the new ciphersuite.
   *connection_status |= cipher_suite;
 }
 
 inline void SSLConnectionStatusSetVersion(int version, int* connection_status) {
   DCHECK_GT(version, 0);
   DCHECK_LT(version, SSL_CONNECTION_VERSION_MAX);
 
   // Clear out the old version.
   *connection_status &=
       ~(SSL_CONNECTION_VERSION_MASK << SSL_CONNECTION_VERSION_SHIFT);
   // Set the new version.
   *connection_status |=
       ((version & SSL_CONNECTION_VERSION_MASK) << SSL_CONNECTION_VERSION_SHIFT);
 }
 
 }  // namespace net
 
 #endif  // NET_SSL_SSL_CONNECTION_STATUS_FLAGS_H_