Revert of [debugger api] remove legacy JSON debug protocol.

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 118 matching lines @@
   // Emits an event with a tag, and some resource usage information.
   // -> (name, tag, <rusage information>).
   // Currently, the resource usage information is a process time stamp
   // and a real time timestamp.
   void ResourceEvent(const char* name, const char* tag);
 
   // Emits an event that an undefined property was read from an
   // 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);
   void ApiIndexedPropertyAccess(const char* tag,
                                 JSObject* holder,
                                 uint32_t index);
   void ApiObjectAccess(const char* tag, JSObject* obj);
   void ApiEntryCall(const char* name);
 
   // ==== Events logged by --log-code. ====
@@ skipping 245 matching lines @@
 
   NameBuffer* name_buffer_;
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 
 #endif  // V8_LOG_H_