[debug] remove deprecated debug command message queue.

include/v8-debug.h

Index: include/v8-debug.h
diff --git a/include/v8-debug.h b/include/v8-debug.h
index 6eaf8806b4d0be9564dce518611b2fba7a48d2f4..77095b95eb4ad1ccb57acccb198e116a2b5de9e3 100644
--- a/include/v8-debug.h
+++ b/include/v8-debug.h
@@ -38,7 +38,7 @@ class V8_EXPORT Debug {
   /**
    * A message object passed to the debug message handler.
    */
-  class Message {
+  V8_DEPRECATED("No longer supported", class Message {
    public:
     /**
      * Check type of message.
@@ -85,8 +85,7 @@ class V8_EXPORT Debug {
     virtual Isolate* GetIsolate() const = 0;
 
     virtual ~Message() {}
-  };
-
+  });
 
   /**
    * An event details object passed to the debug event listener.
@@ -145,10 +144,11 @@ class V8_EXPORT Debug {
    *
    * \param message the debug message handler message object
    *
-   * A MessageHandler2 does not take possession of the message data,
+   * A MessageHandler does not take possession of the message data,
    * and must not rely on the data persisting after the handler returns.
    */
-  typedef void (*MessageHandler)(const Message& message);
+  V8_DEPRECATED("No longer supported",
+                typedef void (*MessageHandler)(const Message& message));
 
   /**
    * Callback function for the host to ensure debug messages are processed.