Add setting break points by using handles

src/debug-delay.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1255 matching lines @@
   var type = request.arguments.type;
   var target = request.arguments.target;
   var line = request.arguments.line;
   var column = request.arguments.column;
   var enabled = IS_UNDEFINED(request.arguments.enabled) ?
       true : request.arguments.enabled;
   var condition = request.arguments.condition;
   var ignoreCount = request.arguments.ignoreCount;
 
   // Check for legal arguments.
-  if (!type || !target) {
+  if (!type || IS_UNDEFINED(target)) {
     response.failed('Missing argument "type" or "target"');
     return;
   }
-  if (type != 'function' && type != 'script' && type != 'scriptId') {
+  if (type != 'function' && type != 'handle' &&
+      type != 'script' && type != 'scriptId') {
     response.failed('Illegal type "' + type + '"');
     return;
   }
 
   // Either function or script break point.
   var break_point_number;
   if (type == 'function') {
     // Handle function break point.
     if (!IS_STRING(target)) {
       response.failed('Argument "target" is not a string value');
       return;
     }
     var f;
     try {
       // Find the function through a global evaluate.
       f = this.exec_state_.evaluateGlobal(target).value();
     } catch (e) {
       response.failed('Error: "' + %ToString(e) +
                       '" evaluating "' + target + '"');
       return;
     }
     if (!IS_FUNCTION(f)) {
       response.failed('"' + target + '" does not evaluate to a function');
       return;
     }
 
     // Set function break point.
     break_point_number = Debug.setBreakPoint(f, line, column, condition);
+  } else if (type == 'handle') {
+    // Find the object pointed by the specified handle.
+    var handle = parseInt(target, 10);
+    var mirror = LookupMirror(handle);
+    if (!mirror) {
+      return response.failed('Object #' + handle + '# not found');
+    }
+    if (!mirror.isFunction()) {
+      return response.failed('Object #' + handle + '# is not a function');
+    }
+
+    // Set function break point.
+    break_point_number = Debug.setBreakPoint(mirror.value(),
+                                             line, column, condition);
   } else if (type == 'script') {
     // set script break point.
     break_point_number =
         Debug.setScriptBreakPointByName(target, line, column, condition);
   } else {  // type == 'scriptId.
     break_point_number =
         Debug.setScriptBreakPointById(target, line, column, condition);
   }
 
   // Set additional break point properties.
@@ skipping 535 matching lines @@
       json += NumberToJSON_(elem);
     } else if (IS_STRING(elem)) {
       json += StringToJSON_(elem);
     } else {
       json += elem;
     }
   }
   json += ']';
   return json;
 }