Fix error in CheckedNumeric usage comment

base/numerics/safe_math.h

 // Copyright 2014 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 BASE_NUMERICS_SAFE_MATH_H_
 #define BASE_NUMERICS_SAFE_MATH_H_
 
 #include <stddef.h>
 
 #include "base/numerics/safe_math_impl.h"
@@ skipping 20 matching lines @@
 //
 // Bitwise operations are explicitly not supported, because correct
 // handling of some cases (e.g. sign manipulation) is ambiguous. Comparison
 // operations are explicitly not supported because they could result in a crash
 // on a CHECK condition. You should use patterns like the following for these
 // operations:
 // Bitwise operation:
 //     CheckedNumeric<int> checked_int = untrusted_input_value;
 //     int x = checked_int.ValueOrDefault(0) | kFlagValues;
 // Comparison:
-//   CheckedNumeric<size_t> checked_size;
-//   CheckedNumeric<int> checked_size = untrusted_input_value;
-//   checked_size = checked_size + HEADER LENGTH;
+//   CheckedNumeric<size_t> checked_size = untrusted_input_value;
+//   checked_size += HEADER LENGTH;
 //   if (checked_size.IsValid() && checked_size.ValueOrDie() < buffer_size)
 //     Do stuff...
 template <typename T>
 class CheckedNumeric {
  public:
   typedef T type;
 
   CheckedNumeric() {}
 
   // Copy constructor.
@@ skipping 237 matching lines @@
 
 #undef BASE_NUMERIC_ARITHMETIC_OPERATORS
 
 }  // namespace internal
 
 using internal::CheckedNumeric;
 
 }  // namespace base
 
 #endif  // BASE_NUMERICS_SAFE_MATH_H_