Mojo C++ Bindings: Add helpers for bad message reporting

mojo/edk/system/core.cc

 // Copyright 2013 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/system/core.h"
 
 #include <string.h>
 
 #include <utility>
 
@@ skipping 149 matching lines @@
   if (!node_controller_)
     node_controller_.reset(new NodeController(this));
   return node_controller_.get();
 }
 
 scoped_refptr<Dispatcher> Core::GetDispatcher(MojoHandle handle) {
   base::AutoLock lock(handles_lock_);
   return handles_.GetDispatcher(handle);
 }
 
+void Core::SetDefaultProcessErrorCallback(
+    const ProcessErrorCallback& callback) {
+  default_process_error_callback_ = callback;
+}
+
 void Core::AddChild(base::ProcessHandle process_handle,
                     ScopedPlatformHandle platform_handle,
                     const std::string& child_token,
                     const ProcessErrorCallback& process_error_callback) {
   GetNodeController()->ConnectToChild(process_handle,
                                       std::move(platform_handle),
                                       child_token,
                                       process_error_callback);
 }
 
@@ skipping 585 matching lines @@
 MojoResult Core::NotifyBadMessage(MojoMessageHandle message,
                                   const char* error,
                                   size_t error_num_bytes) {
   if (!message)
     return MOJO_RESULT_INVALID_ARGUMENT;
 
   const PortsMessage& ports_message =
       reinterpret_cast<MessageForTransit*>(message)->ports_message();
   if (ports_message.source_node() == ports::kInvalidNodeName) {
     DVLOG(1) << "Received invalid message from unknown node.";
+    if (!default_process_error_callback_.is_null())
+      default_process_error_callback_.Run(std::string(error, error_num_bytes));
     return MOJO_RESULT_OK;
   }
 
   GetNodeController()->NotifyBadMessageFrom(
       ports_message.source_node(), std::string(error, error_num_bytes));
   return MOJO_RESULT_OK;
 }
 
 MojoResult Core::CreateDataPipe(
     const MojoCreateDataPipeOptions* options,
@@ skipping 387 matching lines @@
     std::unique_ptr<NodeController> node_controller) {
   // It's OK to leak this reference. At this point we know the IO loop is still
   // running, and we know the NodeController will observe its eventual
   // destruction. This tells the NodeController to delete itself when that
   // happens.
   node_controller.release()->DestroyOnIOThreadShutdown();
 }
 
 }  // namespace edk
 }  // namespace mojo