Debugging for https://crbug.com/601435.

mojo/edk/js/handle.cc

 // Copyright 2014 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 "mojo/edk/js/handle.h"
 
 #include "mojo/edk/js/handle_close_observer.h"
 
 namespace mojo {
 namespace edk {
 namespace js {
 
 gin::WrapperInfo HandleWrapper::kWrapperInfo = { gin::kEmbedderNativeGin };
 
 HandleWrapper::HandleWrapper(MojoHandle handle)
-    : handle_(mojo::Handle(handle)) {
+    : handle_(mojo::Handle(handle)), handle_value_(handle) {
+  LOG(INFO) << "Create " << handle_->value();
 }
 
 HandleWrapper::~HandleWrapper() {
   NotifyCloseObservers();
+  LOG(INFO) << "Delete " << handle_->value() << " (" << handle_value_ << ")";
 }
 
 void HandleWrapper::Close() {
   NotifyCloseObservers();
+  LOG(INFO) << "Close " << handle_->value();
   handle_.reset();
 }
 
 void HandleWrapper::AddCloseObserver(HandleCloseObserver* observer) {
   close_observers_.AddObserver(observer);
 }
 
 void HandleWrapper::RemoveCloseObserver(HandleCloseObserver* observer) {
   close_observers_.RemoveObserver(observer);
 }
@@ skipping 40 matching lines @@
   return Converter<mojo::Handle>::ToV8(isolate, val);
 }
 
 bool Converter<mojo::MessagePipeHandle>::FromV8(v8::Isolate* isolate,
                                                 v8::Handle<v8::Value> val,
                                                 mojo::MessagePipeHandle* out) {
   return Converter<mojo::Handle>::FromV8(isolate, val, out);
 }
 
 }  // namespace gin