Adds some code to help isolate where crash is happening

components/message_port/web_message_port_channel_impl.cc

 // Copyright 2015 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 "components/message_port/web_message_port_channel_impl.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/strings/string16.h"
 #include "third_party/WebKit/public/platform/WebMessagePortChannelClient.h"
@@ skipping 17 matching lines @@
     NOTREACHED();
     return;
   }
 
   *channel1 = new WebMessagePortChannelImpl(pipe1.Pass());;
   *channel2 = new WebMessagePortChannelImpl(pipe2.Pass());
 }
 
 WebMessagePortChannelImpl::WebMessagePortChannelImpl(
     mojo::ScopedMessagePipeHandle pipe)
-    : client_(nullptr), pipe_(pipe.Pass()) {
+    : client_(nullptr), pipe_(pipe.Pass()), handle_watcher_(13) {
   WaitForNextMessage();
 }
 
 WebMessagePortChannelImpl::~WebMessagePortChannelImpl() {
 }
 
 void WebMessagePortChannelImpl::setClient(WebMessagePortChannelClient* client) {
   client_ = client;
 }
 
@@ skipping 82 matching lines @@
     return;
 
   DCHECK_EQ(MOJO_RESULT_OK, result);
   if (!client_)
     return;
   client_->messageAvailable();
   WaitForNextMessage();
 }
 
 }  // namespace message_port