Moving host status events monitoring to a separate interface (HostStatusMonitor).

This CL unbinds the host status event observers from ChromotingHost. This is useful when, for instance, an observer resides in a different process where ChromotingHost is not available. Additionally, observers get HostStatusMonitor as a weak pointer, making sure that they do not need to worry about HostStatusMonitor's life time.

BUG=178873


Review URL: https://chromiumcodereview.appspot.com/12386035

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@185684 0039d316-1c4b-4281-b951-d872f2087c98

18 files changed, 158 insertions, 80 deletions

diff --git a/remoting/host/chromoting_host.cc b/remoting/host/chromoting_host.cc
index 848b926..68009d4 100644
--- a/remoting/host/chromoting_host.cc
+++ b/remoting/host/chromoting_host.cc
@@ -78,7 +78,8 @@ ChromotingHost::ChromotingHost(
       protocol_config_(protocol::CandidateSessionConfig::CreateDefault()),
       login_backoff_(&kDefaultBackoffPolicy),
       authenticating_client_(false),
-      reject_authenticating_client_(false) {
+      reject_authenticating_client_(false),
+      ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)) {
   DCHECK(signal_strategy);
   DCHECK(network_task_runner_->BelongsToCurrentThread());
 
@@ -409,6 +410,8 @@ void ChromotingHost::ShutdownFinish() {
     it->Run();
   }
   shutdown_tasks_.clear();
+
+  weak_factory_.InvalidateWeakPtrs();
 }
 
 }  // namespace remoting
diff --git a/remoting/host/chromoting_host.h b/remoting/host/chromoting_host.h
index bfd4dca..d755744 100644
--- a/remoting/host/chromoting_host.h
+++ b/remoting/host/chromoting_host.h
@@ -10,11 +10,13 @@
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/threading/thread.h"
 #include "net/base/backoff_entry.h"
 #include "remoting/host/client_session.h"
 #include "remoting/host/host_key_pair.h"
+#include "remoting/host/host_status_monitor.h"
 #include "remoting/host/host_status_observer.h"
 #include "remoting/host/mouse_move_observer.h"
 #include "remoting/protocol/authenticator.h"
@@ -62,6 +64,7 @@ class DesktopEnvironmentFactory;
 class ChromotingHost : public base::RefCountedThreadSafe<ChromotingHost>,
                        public ClientSession::EventHandler,
                        public protocol::SessionManager::Listener,
+                       public HostStatusMonitor,
                        public MouseMoveObserver {
  public:
   // The caller must ensure that |signal_strategy| and
@@ -90,10 +93,9 @@ class ChromotingHost : public base::RefCountedThreadSafe<ChromotingHost>,
   // called after shutdown is completed.
   void Shutdown(const base::Closure& shutdown_task);
 
-  // Add/Remove |observer| to/from the list of status observers. Both
-  // methods can be called on the network thread only.
-  void AddStatusObserver(HostStatusObserver* observer);
-  void RemoveStatusObserver(HostStatusObserver* observer);
+  // HostStatusMonitor interface.
+  virtual void AddStatusObserver(HostStatusObserver* observer) OVERRIDE;
+  virtual void RemoveStatusObserver(HostStatusObserver* observer) OVERRIDE;
 
   // This method may be called only from
   // HostStatusObserver::OnClientAuthenticated() to reject the new
@@ -151,6 +153,10 @@ class ChromotingHost : public base::RefCountedThreadSafe<ChromotingHost>,
   // clients that were not connected when this method is called.
   void DisconnectAllClients();
 
+  base::WeakPtr<ChromotingHost> AsWeakPtr() {
+    return weak_factory_.GetWeakPtr();
+  }
+
  private:
   friend class base::RefCountedThreadSafe<ChromotingHost>;
   friend class ChromotingHostTest;
@@ -211,6 +217,8 @@ class ChromotingHost : public base::RefCountedThreadSafe<ChromotingHost>,
   // The maximum duration of any session.
   base::TimeDelta max_session_duration_;
 
+  base::WeakPtrFactory<ChromotingHost> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(ChromotingHost);
 };
 
diff --git a/remoting/host/curtaining_host_observer.cc b/remoting/host/curtaining_host_observer.cc
index 6eacabe..31bb411 100644
--- a/remoting/host/curtaining_host_observer.cc
+++ b/remoting/host/curtaining_host_observer.cc
@@ -6,18 +6,19 @@
 
 #include "base/logging.h"
 #include "remoting/host/curtain_mode.h"
-#include "remoting/host/chromoting_host.h"
+#include "remoting/host/host_status_monitor.h"
 
 namespace remoting {
 
 CurtainingHostObserver::CurtainingHostObserver(
-    CurtainMode *curtain, scoped_refptr<ChromotingHost> host)
-    : curtain_(curtain), host_(host) {
-  host_->AddStatusObserver(this);
+    CurtainMode *curtain, base::WeakPtr<HostStatusMonitor> monitor)
+    : curtain_(curtain), monitor_(monitor) {
+  monitor_->AddStatusObserver(this);
 }
 
 CurtainingHostObserver::~CurtainingHostObserver() {
-  host_->RemoveStatusObserver(this);
+  if (monitor_)
+    monitor_->RemoveStatusObserver(this);
   curtain_->SetActivated(false);
 }
 
diff --git a/remoting/host/curtaining_host_observer.h b/remoting/host/curtaining_host_observer.h
index a952344..20771f4 100644
--- a/remoting/host/curtaining_host_observer.h
+++ b/remoting/host/curtaining_host_observer.h
@@ -10,19 +10,19 @@
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
-#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "remoting/host/host_status_observer.h"
 
 namespace remoting {
 
 class CurtainMode;
-class ChromotingHost;
+class HostStatusMonitor;
 
 class CurtainingHostObserver : public HostStatusObserver {
  public:
   CurtainingHostObserver(CurtainMode *curtain,
-                         scoped_refptr<ChromotingHost> host);
+                         base::WeakPtr<HostStatusMonitor> monitor);
   virtual ~CurtainingHostObserver();
 
   // Enables/disables curtaining when one or more clients are connected.
@@ -35,7 +35,7 @@ class CurtainingHostObserver : public HostStatusObserver {
 
  private:
   CurtainMode* curtain_;
-  scoped_refptr<ChromotingHost> host_;
+  base::WeakPtr<HostStatusMonitor> monitor_;
   std::set<std::string> active_clients_;
   bool enable_curtaining_;
 };
diff --git a/remoting/host/host_event_logger.h b/remoting/host/host_event_logger.h
index b039b3b..92dd81e 100644
--- a/remoting/host/host_event_logger.h
+++ b/remoting/host/host_event_logger.h
@@ -10,10 +10,11 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 
 namespace remoting {
 
-class ChromotingHost;
+class HostStatusMonitor;
 
 class HostEventLogger {
  public:
@@ -22,7 +23,8 @@ class HostEventLogger {
   // Creates an event-logger that monitors host status changes and logs
   // corresponding events to the OS-specific log (syslog/EventLog).
   static scoped_ptr<HostEventLogger> Create(
-      ChromotingHost* host, const std::string& application_name);
+      base::WeakPtr<HostStatusMonitor> monitor,
+      const std::string& application_name);
 
  protected:
   HostEventLogger() {}
diff --git a/remoting/host/host_event_logger_posix.cc b/remoting/host/host_event_logger_posix.cc
index fed6203..6cd7412 100644
--- a/remoting/host/host_event_logger_posix.cc
+++ b/remoting/host/host_event_logger_posix.cc
@@ -4,11 +4,11 @@
 
 #include "remoting/host/host_event_logger.h"
 
-#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/stringprintf.h"
 #include "net/base/ip_endpoint.h"
-#include "remoting/host/chromoting_host.h"
+#include "remoting/host/host_status_monitor.h"
 #include "remoting/host/host_status_observer.h"
 #include "remoting/protocol/transport.h"
 
@@ -23,7 +23,7 @@ namespace {
 
 class HostEventLoggerPosix : public HostEventLogger, public HostStatusObserver {
  public:
-  HostEventLoggerPosix(ChromotingHost* host,
+  HostEventLoggerPosix(base::WeakPtr<HostStatusMonitor> monitor,
                        const std::string& application_name);
 
   virtual ~HostEventLoggerPosix();
@@ -43,7 +43,7 @@ class HostEventLoggerPosix : public HostEventLogger, public HostStatusObserver {
  private:
   void Log(const std::string& message);
 
-  scoped_refptr<ChromotingHost> host_;
+  base::WeakPtr<HostStatusMonitor> monitor_;
   std::string application_name_;
 
   DISALLOW_COPY_AND_ASSIGN(HostEventLoggerPosix);
@@ -51,16 +51,18 @@ class HostEventLoggerPosix : public HostEventLogger, public HostStatusObserver {
 
 } //namespace
 
-HostEventLoggerPosix::HostEventLoggerPosix(ChromotingHost* host,
-                                           const std::string& application_name)
-    : host_(host),
+HostEventLoggerPosix::HostEventLoggerPosix(
+    base::WeakPtr<HostStatusMonitor> monitor,
+    const std::string& application_name)
+    : monitor_(monitor),
       application_name_(application_name) {
   openlog(application_name_.c_str(), 0, LOG_USER);
-  host_->AddStatusObserver(this);
+  monitor_->AddStatusObserver(this);
 }
 
 HostEventLoggerPosix::~HostEventLoggerPosix() {
-  host_->RemoveStatusObserver(this);
+  if (monitor_)
+    monitor_->RemoveStatusObserver(this);
   closelog();
 }
 
@@ -102,9 +104,10 @@ void HostEventLoggerPosix::Log(const std::string& message) {
 
 // static
 scoped_ptr<HostEventLogger> HostEventLogger::Create(
-    ChromotingHost* host, const std::string& application_name) {
+    base::WeakPtr<HostStatusMonitor> monitor,
+    const std::string& application_name) {
   return scoped_ptr<HostEventLogger>(
-      new HostEventLoggerPosix(host, application_name));
+      new HostEventLoggerPosix(monitor, application_name));
 }
 
 }  // namespace remoting
diff --git a/remoting/host/host_event_logger_win.cc b/remoting/host/host_event_logger_win.cc
index 7e13a40..a0a30c9 100644
--- a/remoting/host/host_event_logger_win.cc
+++ b/remoting/host/host_event_logger_win.cc
@@ -8,12 +8,12 @@
 #include <string>
 #include <vector>
 
-#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/string16.h"
 #include "base/utf_string_conversions.h"
 #include "net/base/ip_endpoint.h"
-#include "remoting/host/chromoting_host.h"
+#include "remoting/host/host_status_monitor.h"
 #include "remoting/host/host_status_observer.h"
 #include "remoting/protocol/transport.h"
 
@@ -25,7 +25,8 @@ namespace {
 
 class HostEventLoggerWin : public HostEventLogger, public HostStatusObserver {
  public:
-  HostEventLoggerWin(ChromotingHost* host, const std::string& application_name);
+  HostEventLoggerWin(base::WeakPtr<HostStatusMonitor> monitor,
+                     const std::string& application_name);
 
   virtual ~HostEventLoggerWin();
 
@@ -45,7 +46,7 @@ class HostEventLoggerWin : public HostEventLogger, public HostStatusObserver {
   void LogString(WORD type, DWORD event_id, const std::string& string);
   void Log(WORD type, DWORD event_id, const std::vector<std::string>& strings);
 
-  scoped_refptr<ChromotingHost> host_;
+  base::WeakPtr<HostStatusMonitor> monitor_;
 
   // The handle of the application event log.
   HANDLE event_log_;
@@ -55,14 +56,14 @@ class HostEventLoggerWin : public HostEventLogger, public HostStatusObserver {
 
 } //namespace
 
-HostEventLoggerWin::HostEventLoggerWin(ChromotingHost* host,
+HostEventLoggerWin::HostEventLoggerWin(base::WeakPtr<HostStatusMonitor> monitor,
                                        const std::string& application_name)
-    : host_(host),
+    : monitor_(monitor),
       event_log_(NULL) {
   event_log_ = RegisterEventSourceW(NULL,
                                     UTF8ToUTF16(application_name).c_str());
   if (event_log_ != NULL) {
-    host_->AddStatusObserver(this);
+    monitor_->AddStatusObserver(this);
   } else {
     LOG_GETLASTERROR(ERROR) << "Failed to register the event source: "
                             << application_name;
@@ -71,7 +72,8 @@ HostEventLoggerWin::HostEventLoggerWin(ChromotingHost* host,
 
 HostEventLoggerWin::~HostEventLoggerWin() {
   if (event_log_ != NULL) {
-    host_->RemoveStatusObserver(this);
+    if (monitor_)
+      monitor_->RemoveStatusObserver(this);
     DeregisterEventSource(event_log_);
   }
 }
@@ -147,9 +149,10 @@ void HostEventLoggerWin::LogString(WORD type,
 
 // static
 scoped_ptr<HostEventLogger> HostEventLogger::Create(
-    ChromotingHost* host, const std::string& application_name) {
+    base::WeakPtr<HostStatusMonitor> monitor,
+    const std::string& application_name) {
   return scoped_ptr<HostEventLogger>(
-      new HostEventLoggerWin(host, application_name));
+      new HostEventLoggerWin(monitor, application_name));
 }
 
 }  // namespace remoting
diff --git a/remoting/host/host_status_monitor.h b/remoting/host/host_status_monitor.h
new file mode 100644
index 0000000..6cc80cb
--- /dev/null
+++ b/remoting/host/host_status_monitor.h
@@ -0,0 +1,24 @@
+// Copyright (c) 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.
+
+#ifndef REMOTING_HOST_HOST_STATUS_MONITOR_H_
+#define REMOTING_HOST_HOST_STATUS_MONITOR_H_
+
+namespace remoting {
+
+class HostStatusObserver;
+
+// Interface for registering host status observers.
+class HostStatusMonitor {
+ public:
+  virtual ~HostStatusMonitor() {}
+
+  // Add/Remove |observer| to/from the list of status observers.
+  virtual void AddStatusObserver(HostStatusObserver* observer) = 0;
+  virtual void RemoveStatusObserver(HostStatusObserver* observer) = 0;
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_HOST_STATUS_MONITOR_H_
diff --git a/remoting/host/host_status_monitor_fake.h b/remoting/host/host_status_monitor_fake.h
new file mode 100644
index 0000000..f989ce3
--- /dev/null
+++ b/remoting/host/host_status_monitor_fake.h
@@ -0,0 +1,27 @@
+// Copyright (c) 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.
+
+#ifndef REMOTING_HOST_HOST_STATUS_MONITOR_FAKE_H_
+#define REMOTING_HOST_HOST_STATUS_MONITOR_FAKE_H_
+
+#include "base/memory/weak_ptr.h"
+#include "remoting/host/host_status_monitor.h"
+
+namespace remoting {
+
+// An implementation of HostStatusMonitor that does nothing.
+class HostStatusMonitorFake
+    : public base::SupportsWeakPtr<HostStatusMonitorFake>,
+      public HostStatusMonitor {
+ public:
+  virtual ~HostStatusMonitorFake() {}
+
+  // HostStatusMonitor interface.
+  virtual void AddStatusObserver(HostStatusObserver* observer) OVERRIDE {}
+  virtual void RemoveStatusObserver(HostStatusObserver* observer) OVERRIDE {}
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_HOST_STATUS_MONITOR_FAKE_H_
diff --git a/remoting/host/log_to_server.cc b/remoting/host/log_to_server.cc
index f4830f6..ce2aa64 100644
--- a/remoting/host/log_to_server.cc
+++ b/remoting/host/log_to_server.cc
@@ -7,7 +7,7 @@
 #include "base/bind.h"
 #include "base/message_loop_proxy.h"
 #include "remoting/base/constants.h"
-#include "remoting/host/chromoting_host.h"
+#include "remoting/host/host_status_monitor.h"
 #include "remoting/host/server_log_entry.h"
 #include "remoting/jingle_glue/iq_sender.h"
 #include "remoting/jingle_glue/signal_strategy.h"
@@ -20,25 +20,22 @@ using buzz::XmlElement;
 
 namespace remoting {
 
-LogToServer::LogToServer(ChromotingHost* host,
+LogToServer::LogToServer(base::WeakPtr<HostStatusMonitor> monitor,
                          ServerLogEntry::Mode mode,
                          SignalStrategy* signal_strategy,
                          const std::string& directory_bot_jid)
-    : host_(host),
+    : monitor_(monitor),
       mode_(mode),
       signal_strategy_(signal_strategy),
       directory_bot_jid_(directory_bot_jid) {
+  monitor_->AddStatusObserver(this);
   signal_strategy_->AddListener(this);
-
-  // |host| may be NULL in tests.
-  if (host_)
-    host_->AddStatusObserver(this);
 }
 
 LogToServer::~LogToServer() {
   signal_strategy_->RemoveListener(this);
-  if (host_)
-    host_->RemoveStatusObserver(this);
+  if (monitor_)
+    monitor_->RemoveStatusObserver(this);
 }
 
 void LogToServer::LogSessionStateChange(const std::string& jid,
diff --git a/remoting/host/log_to_server.h b/remoting/host/log_to_server.h
index e65adae..bbd920c 100644
--- a/remoting/host/log_to_server.h
+++ b/remoting/host/log_to_server.h
@@ -9,8 +9,8 @@
 #include <map>
 #include <string>
 
-#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/threading/non_thread_safe.h"
 #include "remoting/host/host_status_observer.h"
 #include "remoting/host/server_log_entry.h"
@@ -27,7 +27,7 @@ class XmlElement;
 
 namespace remoting {
 
-class ChromotingHost;
+class HostStatusMonitor;
 class IqSender;
 
 // LogToServer sends log entries to a server.
@@ -37,7 +37,7 @@ class LogToServer : public base::NonThreadSafe,
                     public HostStatusObserver,
                     public SignalStrategy::Listener {
  public:
-  explicit LogToServer(ChromotingHost* host,
+  explicit LogToServer(base::WeakPtr<HostStatusMonitor> monitor,
                        ServerLogEntry::Mode mode,
                        SignalStrategy* signal_strategy,
                        const std::string& directory_bot_jid);
@@ -65,7 +65,7 @@ class LogToServer : public base::NonThreadSafe,
   void Log(const ServerLogEntry& entry);
   void SendPendingEntries();
 
-  scoped_refptr<ChromotingHost> host_;
+  base::WeakPtr<HostStatusMonitor> monitor_;
   ServerLogEntry::Mode mode_;
   SignalStrategy* signal_strategy_;
   scoped_ptr<IqSender> iq_sender_;
diff --git a/remoting/host/log_to_server_unittest.cc b/remoting/host/log_to_server_unittest.cc
index 4277e49..1fb0500 100644
--- a/remoting/host/log_to_server_unittest.cc
+++ b/remoting/host/log_to_server_unittest.cc
@@ -4,10 +4,11 @@
 
 #include "base/message_loop.h"
 #include "base/message_loop_proxy.h"
-#include "remoting/jingle_glue/mock_objects.h"
+#include "remoting/host/host_status_monitor_fake.h"
 #include "remoting/host/log_to_server.h"
-#include "testing/gmock_mutant.h"
+#include "remoting/jingle_glue/mock_objects.h"
 #include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gmock_mutant.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/libjingle/source/talk/xmllite/xmlelement.h"
 
@@ -126,7 +127,9 @@ class LogToServerTest : public testing::Test {
     message_loop_proxy_ = base::MessageLoopProxy::current();
     EXPECT_CALL(signal_strategy_, AddListener(_));
     log_to_server_.reset(
-        new LogToServer(NULL, ServerLogEntry::ME2ME, &signal_strategy_,
+        new LogToServer(host_status_monitor_.AsWeakPtr(),
+                        ServerLogEntry::ME2ME,
+                        &signal_strategy_,
                         kTestBotJid));
     EXPECT_CALL(signal_strategy_, RemoveListener(_));
   }
@@ -136,6 +139,7 @@ class LogToServerTest : public testing::Test {
   scoped_refptr<base::MessageLoopProxy> message_loop_proxy_;
   MockSignalStrategy signal_strategy_;
   scoped_ptr<LogToServer> log_to_server_;
+  HostStatusMonitorFake host_status_monitor_;
 };
 
 TEST_F(LogToServerTest, SendNow) {
diff --git a/remoting/host/plugin/host_script_object.cc b/remoting/host/plugin/host_script_object.cc
index 02ade7b..1346bce 100644
--- a/remoting/host/plugin/host_script_object.cc
+++ b/remoting/host/plugin/host_script_object.cc
@@ -388,8 +388,8 @@ void HostNPScriptObject::It2MeImpl::FinishConnect(
       host_context_->ui_task_runner());
   host_->AddStatusObserver(this);
   log_to_server_.reset(
-      new LogToServer(host_, ServerLogEntry::IT2ME, signal_strategy_.get(),
-                      directory_bot_jid_));
+      new LogToServer(host_->AsWeakPtr(), ServerLogEntry::IT2ME,
+                      signal_strategy_.get(), directory_bot_jid_));
 
   // Disable audio by default.
   // TODO(sergeyu): Add UI to enable it.
@@ -403,7 +403,8 @@ void HostNPScriptObject::It2MeImpl::FinishConnect(
                                     base::Bind(&It2MeImpl::Disconnect, this));
 
   // Create event logger.
-  host_event_logger_ = HostEventLogger::Create(host_, kApplicationName);
+  host_event_logger_ =
+      HostEventLogger::Create(host_->AsWeakPtr(), kApplicationName);
 
   // Connect signaling and start the host.
   signal_strategy_->Connect();
diff --git a/remoting/host/remoting_me2me_host.cc b/remoting/host/remoting_me2me_host.cc
index e645f81..2d1a3b7 100644
--- a/remoting/host/remoting_me2me_host.cc
+++ b/remoting/host/remoting_me2me_host.cc
@@ -935,17 +935,18 @@ void HostProcess::StartHost() {
       this, host_id_, signal_strategy_.get(), directory_bot_jid_));
 
   log_to_server_.reset(
-      new LogToServer(host_, ServerLogEntry::ME2ME, signal_strategy_.get(),
-                      directory_bot_jid_));
-  host_event_logger_ = HostEventLogger::Create(host_, kApplicationName);
+      new LogToServer(host_->AsWeakPtr(), ServerLogEntry::ME2ME,
+                      signal_strategy_.get(), directory_bot_jid_));
+  host_event_logger_ =
+      HostEventLogger::Create(host_->AsWeakPtr(), kApplicationName);
 
   resizing_host_observer_.reset(
-      new ResizingHostObserver(desktop_resizer_.get(), host_));
+      new ResizingHostObserver(desktop_resizer_.get(), host_->AsWeakPtr()));
 
   // Create a host observer to enable/disable curtain mode as clients connect
   // and disconnect.
   curtaining_host_observer_.reset(new CurtainingHostObserver(
-                                  curtain_.get(), host_));
+                                  curtain_.get(), host_->AsWeakPtr()));
   curtaining_host_observer_->SetEnableCurtaining(curtain_required_);
 
   if (host_user_interface_.get()) {
diff --git a/remoting/host/resizing_host_observer.cc b/remoting/host/resizing_host_observer.cc
index 48742ca..e1c96b5 100644
--- a/remoting/host/resizing_host_observer.cc
+++ b/remoting/host/resizing_host_observer.cc
@@ -3,28 +3,27 @@
 // found in the LICENSE file.
 
 #include "remoting/host/resizing_host_observer.h"
-#include "remoting/host/desktop_resizer.h"
 
 #include <set>
 
 #include "base/logging.h"
+#include "remoting/host/desktop_resizer.h"
+#include "remoting/host/host_status_monitor.h"
 
 namespace remoting {
 
 ResizingHostObserver::ResizingHostObserver(
-    DesktopResizer* desktop_resizer, ChromotingHost* host)
+    DesktopResizer* desktop_resizer,
+    base::WeakPtr<HostStatusMonitor> monitor)
     : desktop_resizer_(desktop_resizer),
-      host_(host),
+      monitor_(monitor),
       original_size_(SkISize::Make(0, 0)) {
-  if (host_ != NULL) {
-    host_->AddStatusObserver(this);
-  }
+  monitor_->AddStatusObserver(this);
 }
 
 ResizingHostObserver::~ResizingHostObserver() {
-  if (host_ != NULL) {
-    host_->RemoveStatusObserver(this);
-  }
+  if (monitor_)
+    monitor_->RemoveStatusObserver(this);
 }
 
 void ResizingHostObserver::OnClientAuthenticated(const std::string& jid) {
diff --git a/remoting/host/resizing_host_observer.h b/remoting/host/resizing_host_observer.h
index 1c23b75..85c23f1 100644
--- a/remoting/host/resizing_host_observer.h
+++ b/remoting/host/resizing_host_observer.h
@@ -7,23 +7,24 @@
 
 #include <string>
 
-#include "remoting/host/host_status_observer.h"
-#include "remoting/host/chromoting_host.h"
-
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
+#include "base/memory/weak_ptr.h"
+#include "remoting/host/host_status_observer.h"
 #include "third_party/skia/include/core/SkSize.h"
 
 namespace remoting {
 
 class DesktopResizer;
+class HostStatusMonitor;
 
 // Use the specified DesktopResizer to match host desktop size to the client
 // view size as closely as is possible. When the connection closes, restore
 // the original desktop size.
 class ResizingHostObserver : public HostStatusObserver {
  public:
-  ResizingHostObserver(DesktopResizer* desktop_resizer, ChromotingHost* host);
+  ResizingHostObserver(DesktopResizer* desktop_resizer,
+                       base::WeakPtr<HostStatusMonitor> monitor);
   virtual ~ResizingHostObserver();
 
   // HostStatusObserver interface
@@ -35,7 +36,7 @@ class ResizingHostObserver : public HostStatusObserver {
 
  private:
   DesktopResizer* const desktop_resizer_;
-  scoped_refptr<ChromotingHost> host_;
+  base::WeakPtr<HostStatusMonitor> monitor_;
   SkISize original_size_;
   std::string client_jid_;
 
diff --git a/remoting/host/resizing_host_observer_unittest.cc b/remoting/host/resizing_host_observer_unittest.cc
index 3d5d1e0..ec0ae10 100644
--- a/remoting/host/resizing_host_observer_unittest.cc
+++ b/remoting/host/resizing_host_observer_unittest.cc
@@ -2,13 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "remoting/host/resizing_host_observer.h"
-#include "remoting/host/desktop_resizer.h"
-
 #include <list>
 
 #include "base/compiler_specific.h"
 #include "base/logging.h"
+#include "remoting/host/desktop_resizer.h"
+#include "remoting/host/host_status_monitor_fake.h"
+#include "remoting/host/resizing_host_observer.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkSize.h"
 
@@ -67,8 +67,9 @@ class ResizingHostObserverTest : public testing::Test {
  public:
   void SetDesktopResizer(FakeDesktopResizer* desktop_resizer) {
     CHECK(!desktop_resizer_.get()) << "Call SetDeskopResizer once per test";
-    resizing_host_observer_.reset(new ResizingHostObserver(desktop_resizer,
-                                                           NULL));
+    resizing_host_observer_.reset(
+        new ResizingHostObserver(desktop_resizer,
+                                 host_status_monitor_.AsWeakPtr()));
     desktop_resizer_.reset(desktop_resizer);
     resizing_host_observer_->OnClientAuthenticated("");
   }
@@ -103,6 +104,7 @@ class ResizingHostObserverTest : public testing::Test {
  private:
   scoped_ptr<ResizingHostObserver> resizing_host_observer_;
   scoped_ptr<FakeDesktopResizer> desktop_resizer_;
+  HostStatusMonitorFake host_status_monitor_;
 };
 
 // Check that the host is not resized if GetSupportedSizes returns an empty
diff --git a/remoting/remoting.gyp b/remoting/remoting.gyp
index 0c2472d..71999b5 100644
--- a/remoting/remoting.gyp
+++ b/remoting/remoting.gyp
@@ -359,6 +359,7 @@
             'host/host_port_allocator.h',
             'host/host_secret.cc',
             'host/host_secret.h',
+            'host/host_status_monitor.h',
             'host/host_status_observer.h',
             'host/host_user_interface.cc',
             'host/host_user_interface.h',
@@ -2485,6 +2486,7 @@
         'host/host_key_pair_unittest.cc',
         'host/host_mock_objects.cc',
         'host/host_mock_objects.h',
+        'host/host_status_monitor_fake.h',
         'host/ipc_desktop_environment_unittest.cc',
         'host/json_host_config_unittest.cc',
         'host/linux/x_server_clipboard_unittest.cc',