Re-submit http://codereview.chromium.org/99122

include/v8-debug.h

Index: include/v8-debug.h
===================================================================
--- include/v8-debug.h	(revision 1812)
+++ include/v8-debug.h	(working copy)
@@ -92,6 +92,57 @@
 
 
   /**
+   * A message object passed to the debug message handler.
+   */
+  class Message {
+   public:
+    /**
+     * Check type of message.
+     */
+    virtual bool IsEvent() const = 0;
+    virtual bool IsResponse() const = 0;
+    virtual DebugEvent GetEvent() const = 0;
+
+    /**
+     * Indicate whether this is a response to a continue command which will
+     * start the VM running after this is processed.
+     */
+    virtual bool WillStartRunning() const = 0;
+
+    /**
+     * Access to execution state and event data. Don't store these cross
+     * callbacks as their content becomes invalid. These objects are from the
+     * debugger event that started the debug message loop.
+     */
+    virtual Handle<Object> GetExecutionState() const = 0;
+    virtual Handle<Object> GetEventData() const = 0;
+	
+    /**
+     * Get the debugger protocol JSON.
+     */
+    virtual Handle<String> GetJSON() const = 0;
+
+    /**
+     * Get the context active when the debug event happened. Note this is not
+     * the current active context as the JavaScript part of the debugger is
+     * running in it's own context which is entered at this point.
+     */
+    virtual Handle<Context> GetEventContext() const = 0;
+
+    /**
+     * Client data passed with the corresponding request if any. This is the
+     * client_data data value passed into Debug::SendCommand along with the
+     * request that led to the message or NULL if the message is an event. The
+     * debugger takes ownership of the data and will delete it even if there is
+     * no message handler.
+     */
+    virtual ClientData* GetClientData() const = 0;
+
+    virtual ~Message() {}
+  };
+  
+
+  /**
    * Debug event callback function.
    *
    * \param event the type of the debug event that triggered the callback
@@ -101,26 +152,22 @@
    * \param data value passed by the user to SetDebugEventListener
    */
   typedef void (*EventCallback)(DebugEvent event,
-                                     Handle<Object> exec_state,
-                                     Handle<Object> event_data,
-                                     Handle<Value> data);
+                                Handle<Object> exec_state,
+                                Handle<Object> event_data,
+                                Handle<Value> data);
 
 
   /**
    * Debug message callback function.
    *
-   * \param message the debug message
+   * \param message the debug message handler message object
    * \param length length of the message
    * \param data the data value passed when registering the message handler
-   * \param client_data the data value passed into Debug::SendCommand along
-   *     with the request that led to the message or NULL if the message is an
-   *     asynchronous event. The debugger takes ownership of the data and will
-   *     delete it before dying even if there is no message handler.
+
    * A MessageHandler does not take posession of the message string,
    * and must not rely on the data persisting after the handler returns.
    */
-  typedef void (*MessageHandler)(const uint16_t* message, int length,
-                                      ClientData* client_data);
+  typedef void (*MessageHandler)(const Message& message);
 
   /**
    * Debug host dispatch callback function.