Make V8ValueConverter.FromV8Value behave similarly to JSON.stringify

content/renderer/render_view_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 #include <vector>
@@ skipping 4236 matching lines @@
     result = web_frame->executeScriptAndReturnValue(WebScriptSource(jscript));
   if (notify_result) {
     ListValue list;
     if (!result.IsEmpty() && web_frame) {
       v8::HandleScope handle_scope;
       v8::Local<v8::Context> context = web_frame->mainWorldScriptContext();
       v8::Context::Scope context_scope(context);
       V8ValueConverterImpl converter;
       converter.SetDateAllowed(true);
       converter.SetRegexpAllowed(true);
-      list.Set(0, converter.FromV8Value(result, context));
+      base::Value* result_value = converter.FromV8Value(result, context);
+      list.Set(0, result_value ? result_value :
+                                 base::Value::CreateNullValue());
     } else {
       list.Set(0, Value::CreateNullValue());
     }
     Send(new ViewHostMsg_ScriptEvalResponse(routing_id_, id, list));
   }
 }
 
 bool RenderViewImpl::ShouldDisplayScrollbars(int width, int height) const {
   return (!send_preferred_size_changes_ ||
           (disable_scrollbars_size_limit_.width() <= width ||
@@ skipping 1889 matching lines @@
 
   updating_frame_tree_ = true;
   active_frame_id_map_.clear();
 
   target_process_id_ = process_id;
   target_routing_id_ = route_id;
   CreateFrameTree(webview()->mainFrame(), frames);
 
   updating_frame_tree_ = false;
 }