Make event logger slightly more light-weight.

src/log.h

 // Copyright 2012 the V8 project 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 V8_LOG_H_
 #define V8_LOG_H_
 
 #include <string>
 
 #include "src/allocation.h"
@@ skipping 282 matching lines @@
                           uintptr_t end);
 
   void CodeDeoptEvent(Code* code);
   void CurrentTimeEvent();
 
   void TimerEvent(StartEnd se, const char* name);
 
   static void EnterExternal(Isolate* isolate);
   static void LeaveExternal(Isolate* isolate);
 
-  static inline void CallEventLogger(Isolate* isolate, const char* name,
-                                     StartEnd se, bool expose_to_api);
+  static void DefaultEventLoggerSentinel(const char* name, int event) {}
+
+  INLINE(static void CallEventLogger(Isolate* isolate, const char* name,
+                                     StartEnd se, bool expose_to_api));
 
   // ==== Events logged by --log-regexp ====
   // Regexp compilation and execution events.
 
   void RegExpCompileEvent(Handle<JSRegExp> regexp, bool in_cache);
 
   bool is_logging() {
     return is_logging_;
   }
 
@@ skipping 217 matching lines @@
                                  int length) = 0;
 
   NameBuffer* name_buffer_;
 };
 
 
 } }  // namespace v8::internal
 
 
 #endif  // V8_LOG_H_