[mojo-edk] Fix uninitialized padding in AddBrokerClient message

mojo/edk/system/node_channel.cc

 // Copyright 2016 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/node_channel.h"
 
 #include <cstring>
 #include <limits>
 #include <sstream>
 
@@ skipping 273 matching lines @@
 #if defined(OS_WIN)
   handles->push_back(PlatformHandle(process_handle));
 #endif
   Channel::MessagePtr message = CreateMessage(
       MessageType::ADD_BROKER_CLIENT, sizeof(AddBrokerClientData),
       handles->size(), &data);
   message->SetHandles(std::move(handles));
   data->client_name = client_name;
 #if !defined(OS_WIN)
   data->process_handle = process_handle;
+  data->padding = 0;
 #endif
   WriteChannelMessage(std::move(message));
 }
 
 void NodeChannel::BrokerClientAdded(const ports::NodeName& client_name,
                                     ScopedPlatformHandle broker_channel) {
   BrokerClientAddedData* data;
   ScopedPlatformHandleVectorPtr handles(new PlatformHandleVector());
   if (broker_channel.is_valid())
     handles->push_back(broker_channel.release());
@@ skipping 557 matching lines @@
 
   base::AutoLock lock(channel_lock_);
   if (!channel_)
     DLOG(ERROR) << "Dropping message on closed channel.";
   else
     channel_->Write(std::move(message));
 }
 
 }  // namespace edk
 }  // namespace mojo