[debugger api] remove legacy JSON debug protocol.

src/log.h

Index: src/log.h
diff --git a/src/log.h b/src/log.h
index b7a5fc6bd3cd961c57a039e1aaf2bb2cc15a95cb..78312059343fc239a6e6e27959c881804ddf81ca 100644
--- a/src/log.h
+++ b/src/log.h
@@ -136,12 +136,6 @@ class Logger : public CodeEventListener {
   // object.
   void SuspectReadEvent(Name* name, Object* obj);
 
-  // Emits an event when a message is put on or read from a debugging queue.
-  // DebugTag lets us put a call-site specific label on the event.
-  void DebugTag(const char* call_site_tag);
-  void DebugEvent(const char* event_type, Vector<uint16_t> parameter);
-
-
   // ==== Events logged by --log-api. ====
   void ApiSecurityCheck();
   void ApiNamedPropertyAccess(const char* tag, JSObject* holder, Object* name);