Support 'restart call frame' debug command

src/debug-debugger.js

 // Copyright 2012 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 1431 matching lines @@
       } else if (request.command == 'threads') {
         this.threadsRequest_(request, response);
       } else if (request.command == 'suspend') {
         this.suspendRequest_(request, response);
       } else if (request.command == 'version') {
         this.versionRequest_(request, response);
       } else if (request.command == 'profile') {
         this.profileRequest_(request, response);
       } else if (request.command == 'changelive') {
         this.changeLiveRequest_(request, response);
+      } else if (request.command == 'restartframe') {
+        this.restartFrameRequest_(request, response);
       } else if (request.command == 'flags') {
         this.debuggerFlagsRequest_(request, response);
       } else if (request.command == 'v8flags') {
         this.v8FlagsRequest_(request, response);
 
       // GC tools:
       } else if (request.command == 'gc') {
         this.gcRequest_(request, response);
 
       // LiveObjectList tools:
@@ skipping 889 matching lines @@
     %ProfilerPause();
   } else {
     return response.failed('Unknown command');
   }
   response.body = {};
 };
 
 
 DebugCommandProcessor.prototype.changeLiveRequest_ = function(
     request, response) {
-  if (!Debug.LiveEdit) {
-    return response.failed('LiveEdit feature is not supported');
-  }
   if (!request.arguments) {
     return response.failed('Missing arguments');
   }
   var script_id = request.arguments.script_id;
   var preview_only = !!request.arguments.preview_only;
 
   var scripts = %DebugGetLoadedScripts();
 
   var the_script = null;
   for (var i = 0; i < scripts.length; i++) {
@@ skipping 17 matching lines @@
   var result_description = Debug.LiveEdit.SetScriptSource(the_script,
       new_source, preview_only, change_log);
   response.body = {change_log: change_log, result: result_description};
 
   if (!preview_only && !this.running_ && result_description.stack_modified) {
     response.body.stepin_recommended = true;
   }
 };
 
 
+DebugCommandProcessor.prototype.restartFrameRequest_ = function(
+    request, response) {
+  if (!request.arguments) {
+    return response.failed('Missing arguments');
+  }
+  var frame = request.arguments.frame;
+
+  // No frames to evaluate in frame.
+  if (this.exec_state_.frameCount() == 0) {
+    return response.failed('No frames');
+  }
+
+  var frame_mirror;
+  // Check whether a frame was specified.
+  if (!IS_UNDEFINED(frame)) {
+    var frame_number = %ToNumber(frame);
+    if (frame_number < 0 || frame_number >= this.exec_state_.frameCount()) {
+      return response.failed('Invalid frame "' + frame + '"');
+    }
+    // Restart specified frame.
+    frame_mirror = this.exec_state_.frame(frame_number);
+  } else {
+    // Restart selected frame.
+    frame_mirror = this.exec_state_.frame();
+  }
+
+  var result_description = Debug.LiveEdit.RestartFrame(frame_mirror);
+  response.body = {result: result_description};
+};
+
+
 DebugCommandProcessor.prototype.debuggerFlagsRequest_ = function(request,
                                                                  response) {
   // Check for legal request.
   if (!request.arguments) {
     response.failed('Missing arguments');
     return;
   }
 
   // Pull out arguments.
   var flags = request.arguments.flags;
@@ skipping 215 matching lines @@
     case 'string':
     case 'number':
       json = value;
       break;
 
     default:
       json = null;
   }
   return json;
 }