Clean up public interface of AttachmentBrokerUnprivileged.

In the old interface, a static factory method returns a scoped_ptr, and the
caller had to manage the lifetime. Since this is a global object with minimal
memory footprint, and is required to outlive every IPC::Channel, it's much
easier for the global to never be destroyed. This also matches the interface for
AttachmentBrokerPrivileged.

BUG=584297

Review URL: https://codereview.chromium.org/1679763002

Cr-Commit-Position: refs/heads/master@{#375674}

3 files changed, 14 insertions, 21 deletions

diff --git a/remoting/host/desktop_process.cc b/remoting/host/desktop_process.cc
index b0afa8e..e59b8a5 100644
--- a/remoting/host/desktop_process.cc
+++ b/remoting/host/desktop_process.cc
@@ -82,6 +82,9 @@ void DesktopProcess::OnChannelConnected(int32_t peer_pid) {
 
 void DesktopProcess::OnChannelError() {
   // Shutdown the desktop process.
+  IPC::AttachmentBroker* broker = IPC::AttachmentBroker::GetGlobal();
+  if (broker && !broker->IsPrivilegedBroker())
+    broker->DeregisterBrokerCommunicationChannel(daemon_channel_.get());
   daemon_channel_.reset();
   if (desktop_agent_.get()) {
     desktop_agent_->Stop();
@@ -141,14 +144,10 @@ bool DesktopProcess::Start(
       IPC::ChannelProxy::Create(daemon_channel_name_, IPC::Channel::MODE_CLIENT,
                                 this, io_task_runner.get());
 
-  // Attachment broker may be already created in tests.
-  if (!IPC::AttachmentBroker::GetGlobal())
-    attachment_broker_ = IPC::AttachmentBrokerUnprivileged::CreateBroker();
-
-  if (attachment_broker_) {
-    attachment_broker_->DesignateBrokerCommunicationChannel(
-        daemon_channel_.get());
-  }
+  IPC::AttachmentBrokerUnprivileged::CreateBrokerIfNeeded();
+  IPC::AttachmentBroker* broker = IPC::AttachmentBroker::GetGlobal();
+  if (broker && !broker->IsPrivilegedBroker())
+    broker->RegisterBrokerCommunicationChannel(daemon_channel_.get());
 
   // Pass |desktop_pipe| to the daemon.
   daemon_channel_->Send(
diff --git a/remoting/host/desktop_process.h b/remoting/host/desktop_process.h
index e085c6a..4246724 100644
--- a/remoting/host/desktop_process.h
+++ b/remoting/host/desktop_process.h
@@ -19,7 +19,6 @@
 #include "remoting/host/desktop_session_agent.h"
 
 namespace IPC {
-class AttachmentBrokerUnprivileged;
 class ChannelProxy;
 }  // namespace IPC
 
@@ -77,9 +76,6 @@ class DesktopProcess : public DesktopSessionAgent::Delegate,
   // process.
   std::string daemon_channel_name_;
 
-  // Attachment broker for |daemon_channel_|.
-  scoped_ptr<IPC::AttachmentBrokerUnprivileged> attachment_broker_;
-
   // IPC channel connecting the desktop process with the daemon process.
   scoped_ptr<IPC::ChannelProxy> daemon_channel_;
 
diff --git a/remoting/host/remoting_me2me_host.cc b/remoting/host/remoting_me2me_host.cc
index a80ef55..9004846 100644
--- a/remoting/host/remoting_me2me_host.cc
+++ b/remoting/host/remoting_me2me_host.cc
@@ -461,9 +461,6 @@ class HostProcess : public ConfigWatcher::Delegate,
   // Accessed on the UI thread.
   scoped_ptr<IPC::ChannelProxy> daemon_channel_;
 
-  // AttachmentBroker for |daemon_channel_|.
-  scoped_ptr<IPC::AttachmentBrokerUnprivileged> attachment_broker_;
-
   // Owned as |desktop_environment_factory_|.
   DesktopSessionConnector* desktop_session_connector_ = nullptr;
 #endif  // defined(REMOTING_MULTI_PROCESS)
@@ -545,11 +542,10 @@ bool HostProcess::InitWithCommandLine(const base::CommandLine* cmd_line) {
                                               this,
                                               context_->network_task_runner());
 
-  attachment_broker_ = IPC::AttachmentBrokerUnprivileged::CreateBroker();
-  if (attachment_broker_) {
-    attachment_broker_->DesignateBrokerCommunicationChannel(
-        daemon_channel_.get());
-  }
+  IPC::AttachmentBrokerUnprivileged::CreateBrokerIfNeeded();
+  IPC::AttachmentBroker* broker = IPC::AttachmentBroker::GetGlobal();
+  if (broker && !broker->IsPrivilegedBroker())
+    broker->RegisterBrokerCommunicationChannel(daemon_channel_.get());
 
 #else  // !defined(REMOTING_MULTI_PROCESS)
   if (cmd_line->HasSwitch(kHostConfigSwitchName)) {
@@ -931,7 +927,9 @@ void HostProcess::ShutdownOnUiThread() {
   policy_watcher_.reset();
 
 #if defined(REMOTING_MULTI_PROCESS)
-  attachment_broker_.reset();
+  IPC::AttachmentBroker* broker = IPC::AttachmentBroker::GetGlobal();
+  if (broker && !broker->IsPrivilegedBroker())
+    broker->DeregisterBrokerCommunicationChannel(daemon_channel_.get());
   daemon_channel_.reset();
 #endif  // defined(REMOTING_MULTI_PROCESS)