Fix DCHECK usage doc comment.

base/logging.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 BASE_LOGGING_H_
 #define BASE_LOGGING_H_
 
 #include <stddef.h>
 
 #include <cassert>
@@ skipping 713 matching lines @@
   else                                                                 \
     ::logging::LogMessage(__FILE__, __LINE__, ::logging::LOG_DCHECK,   \
                           true_if_passed.message()).stream()
 
 // Equality/Inequality checks - compare two values, and log a
 // LOG_DCHECK message including the two values when the result is not
 // as expected.  The values must have operator<<(ostream, ...)
 // defined.
 //
 // You may append to the error message like so:
-//   DCHECK_NE(1, 2) << ": The world must be ending!";
+//   DCHECK_NE(1, 2) << "The world must be ending!";
 //
 // We are very careful to ensure that each argument is evaluated exactly
 // once, and that anything which is legal to pass as a function argument is
 // legal here.  In particular, the arguments may be temporary expressions
 // which will end up being destroyed at the end of the apparent statement,
 // for example:
 //   DCHECK_EQ(string("abc")[1], 'b');
 //
 // WARNING: These don't compile correctly if one of the arguments is a pointer
 // and the other is NULL.  In new code, prefer nullptr instead.  To
@@ skipping 243 matching lines @@
 #elif NOTIMPLEMENTED_POLICY == 5
 #define NOTIMPLEMENTED() do {\
   static bool logged_once = false;\
   LOG_IF(ERROR, !logged_once) << NOTIMPLEMENTED_MSG;\
   logged_once = true;\
 } while(0);\
 EAT_STREAM_PARAMETERS
 #endif
 
 #endif  // BASE_LOGGING_H_