Make it a compile error to use a crash key with no variable name.

base/debug/crash_logging.cc

 // 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.
 
 #include "base/debug/crash_logging.h"
 
 #include <cmath>
 #include <map>
 
 #include "base/debug/stack_trace.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 
+#undef ScopedCrashKey
+
 namespace base {
 namespace debug {
 
 namespace {
 
 // Global map of crash key names to registration entries.
 typedef std::map<base::StringPiece, CrashKey> CrashKeyMap;
 CrashKeyMap* g_crash_keys_ = NULL;
 
 // The maximum length of a single chunk.
@@ skipping 168 matching lines @@
 void ResetCrashLoggingForTesting() {
   delete g_crash_keys_;
   g_crash_keys_ = NULL;
   g_chunk_max_length_ = 0;
   g_set_key_func_ = NULL;
   g_clear_key_func_ = NULL;
 }
 
 }  // namespace debug
 }  // namespace base