[mojo-edk] Expose notification source to MojoWatch callbacks

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>
 
 #include "base/logging.h"
 #include "mojo/edk/system/channel.h"
+#include "mojo/edk/system/request_context.h"
 
 namespace mojo {
 namespace edk {
 
 namespace {
 
 template <typename T>
 T Align(T t) {
   const auto k = kChannelMessageAlignment;
   return t + (k - (t % k)) % k;
@@ skipping 317 matching lines @@
 
 NodeChannel::~NodeChannel() {
   ShutDown();
 }
 
 void NodeChannel::OnChannelMessage(const void* payload,
                                    size_t payload_size,
                                    ScopedPlatformHandleVectorPtr handles) {
   DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
 
+  RequestContext request_context(RequestContext::Source::SYSTEM);
+
 #if defined(OS_WIN)
   // If we receive handles from a known process, rewrite them to our own
   // process. This can occur when a privileged node receives handles directly
   // from a privileged descendant.
   {
     base::AutoLock lock(remote_process_handle_lock_);
     if (handles && remote_process_handle_ != base::kNullProcessHandle) {
       if (!Channel::Message::RewriteHandles(remote_process_handle_,
                                             base::GetCurrentProcessHandle(),
                                             handles->data(), handles->size())) {
@@ skipping 151 matching lines @@
                   << static_cast<uint32_t>(header->type) << " from node "
                   << remote_node_name_;
       delegate_->OnChannelError(remote_node_name_);
       break;
   }
 }
 
 void NodeChannel::OnChannelError() {
   DCHECK(io_task_runner_->RunsTasksOnCurrentThread());
 
+  RequestContext request_context(RequestContext::Source::SYSTEM);
+
   ShutDown();
   // |OnChannelError()| may cause |this| to be destroyed, but still need access
   // to the name name after that destruction. So may a copy of
   // |remote_node_name_| so it can be used if |this| becomes destroyed.
   ports::NodeName node_name = remote_node_name_;
   delegate_->OnChannelError(node_name);
 }
 
 void NodeChannel::WriteChannelMessage(Channel::MessagePtr message) {
 #if defined(OS_WIN)
@@ skipping 23 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