Add PluginMessageLoopProxy and use it for Host plugin UI thread.

remoting/host/desktop_environment.cc

 // Copyright (c) 2011 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 "remoting/host/desktop_environment.h"
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "remoting/host/capturer.h"
 #include "remoting/host/chromoting_host.h"
 #include "remoting/host/chromoting_host_context.h"
 #include "remoting/host/continue_window.h"
 #include "remoting/host/curtain.h"
 #include "remoting/host/disconnect_window.h"
 #include "remoting/host/event_executor.h"
 #include "remoting/host/local_input_monitor.h"
 
 static const int kContinueWindowTimeoutMs = 10 * 60 * 1000;
 
 namespace remoting {
 
 // UIThreadProxy proxies DesktopEnvironment method calls to the UI
 // thread. This is neccessary so that DesktopEnvironment can be
 // deleted synchronously even while there are pending tasks on the
 // message queue.
+//
+// TODO(sergeyu): Merge this code with remoting::TaskThreadProxy. The
+// problem solved by this class is very simular to the one solved by
+// ScopedRunnableMethodFactory. The main difference is that this class
+// is thread-safe. Change the interface to make it look more like
+// ScopedRunnableMethodFactory and rename it to avoid confusion with
+// MessageLoopProxy.
 class UIThreadProxy : public base::RefCountedThreadSafe<UIThreadProxy> {
  public:
-  UIThreadProxy(ChromotingHostContext* context)
-      : context_(context) {
+  UIThreadProxy(base::MessageLoopProxy* message_loop)
+      : message_loop_(message_loop) {
   }
 
+  // TODO(sergeyu): Rename this method.
   void Detach() {
-    DCHECK(context_->IsUIThread());
-    context_ = NULL;
+    DCHECK(message_loop_->BelongsToCurrentThread());
+    message_loop_ = NULL;
   }
 
   void CallOnUIThread(const tracked_objects::Location& from_here,
                       const base::Closure& closure) {
-    if (context_) {
-      context_->PostTaskToUIThread(from_here, base::Bind(
+    scoped_refptr<base::MessageLoopProxy> message_loop = message_loop_;
+    if (message_loop) {
+      message_loop->PostTask(from_here, base::Bind(
           &UIThreadProxy::CallClosure, this, closure));
     }
   }
 
   void CallOnUIThreadDelayed(const tracked_objects::Location& from_here,
                              const base::Closure& closure,
                              int delay_ms) {
-    if (context_) {
-      context_->PostDelayedTaskToUIThread(from_here, base::Bind(
+    scoped_refptr<base::MessageLoopProxy> message_loop = message_loop_;
+    if (message_loop) {
+      message_loop->PostDelayedTask(from_here, base::Bind(
           &UIThreadProxy::CallClosure, this, closure), delay_ms);
     }
   }
 
  private:
   friend class base::RefCountedThreadSafe<UIThreadProxy>;
 
   virtual ~UIThreadProxy() { }
 
   void CallClosure(const base::Closure& closure) {
-    if (context_)
+    if (message_loop_)
       closure.Run();
   }
 
-  ChromotingHostContext* context_;
+  scoped_refptr<base::MessageLoopProxy> message_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(UIThreadProxy);
 };
 
 // static
 DesktopEnvironment* DesktopEnvironment::Create(ChromotingHostContext* context) {
   Capturer* capturer = Capturer::Create();
   EventExecutor* event_executor =
       EventExecutor::Create(context->desktop_message_loop(), capturer);
   Curtain* curtain = Curtain::Create();
@@ skipping 16 matching lines @@
     : host_(NULL),
       context_(context),
       capturer_(capturer),
       event_executor_(event_executor),
       curtain_(curtain),
       disconnect_window_(disconnect_window),
       continue_window_(continue_window),
       local_input_monitor_(local_input_monitor),
       is_monitoring_local_inputs_(false),
       continue_timer_started_(false),
-      proxy_(new UIThreadProxy(context)) {
+      proxy_(new UIThreadProxy(context->ui_message_loop())) {
 }
 
 DesktopEnvironment::~DesktopEnvironment() {
 }
 
 void DesktopEnvironment::Shutdown() {
-  DCHECK(context_->IsUIThread());
+  DCHECK(context_->ui_message_loop()->BelongsToCurrentThread());
 
   MonitorLocalInputs(false);
   ShowDisconnectWindow(false, std::string());
   ShowContinueWindow(false);
   StartContinueWindowTimer(false);
 
   proxy_->Detach();
 }
 
 void DesktopEnvironment::OnConnect(const std::string& username) {
   proxy_->CallOnUIThread(FROM_HERE, base::Bind(
       &DesktopEnvironment::ProcessOnConnect, base::Unretained(this), username));
 }
 
 void DesktopEnvironment::OnLastDisconnect() {
   proxy_->CallOnUIThread(FROM_HERE, base::Bind(
       &DesktopEnvironment::ProcessOnLastDisconnect, base::Unretained(this)));
 }
 
 void DesktopEnvironment::OnPause(bool pause) {
   proxy_->CallOnUIThread(FROM_HERE, base::Bind(
       &DesktopEnvironment::ProcessOnPause, base::Unretained(this), pause));
 }
 
 void DesktopEnvironment::ProcessOnConnect(const std::string& username) {
-  DCHECK(context_->IsUIThread());
+  DCHECK(context_->ui_message_loop()->BelongsToCurrentThread());
 
   MonitorLocalInputs(true);
   ShowDisconnectWindow(true, username);
   StartContinueWindowTimer(true);
 }
 
 void DesktopEnvironment::ProcessOnLastDisconnect() {
-  DCHECK(context_->IsUIThread());
+  DCHECK(context_->ui_message_loop()->BelongsToCurrentThread());
 
   MonitorLocalInputs(false);
   ShowDisconnectWindow(false, std::string());
   ShowContinueWindow(false);
   StartContinueWindowTimer(false);
 }
 
 void DesktopEnvironment::ProcessOnPause(bool pause) {
   StartContinueWindowTimer(!pause);
 }
 
 void DesktopEnvironment::MonitorLocalInputs(bool enable) {
-  DCHECK(context_->IsUIThread());
+  DCHECK(context_->ui_message_loop()->BelongsToCurrentThread());
 
   if (enable == is_monitoring_local_inputs_)
     return;
   if (enable) {
     local_input_monitor_->Start(host_);
   } else {
     local_input_monitor_->Stop();
   }
   is_monitoring_local_inputs_ = enable;
 }
 
 void DesktopEnvironment::ShowDisconnectWindow(bool show,
                                               const std::string& username) {
-  DCHECK(context_->IsUIThread());
+  DCHECK(context_->ui_message_loop()->BelongsToCurrentThread());
 
   if (show) {
     disconnect_window_->Show(host_, username);
   } else {
     disconnect_window_->Hide();
   }
 }
 
 void DesktopEnvironment::ShowContinueWindow(bool show) {
-  DCHECK(context_->IsUIThread());
+  DCHECK(context_->ui_message_loop()->BelongsToCurrentThread());
 
   if (show) {
     continue_window_->Show(host_);
   } else {
     continue_window_->Hide();
   }
 }
 
 void DesktopEnvironment::StartContinueWindowTimer(bool start) {
-  DCHECK(context_->IsUIThread());
+  DCHECK(context_->ui_message_loop()->BelongsToCurrentThread());
 
   if (start && !continue_timer_started_) {
     continue_timer_target_time_ = base::Time::Now() +
         base::TimeDelta::FromMilliseconds(kContinueWindowTimeoutMs);
     proxy_->CallOnUIThreadDelayed(
         FROM_HERE, base::Bind(&DesktopEnvironment::ContinueWindowTimerFunc,
                               base::Unretained(this)),
         kContinueWindowTimeoutMs);
   }
 
   continue_timer_started_ = start;
 }
 
 void DesktopEnvironment::ContinueWindowTimerFunc() {
-  DCHECK(context_->IsUIThread());
+  DCHECK(context_->ui_message_loop()->BelongsToCurrentThread());
 
   // This function may be called prematurely if timer was stopped and
   // then started again. In that case we just ignore this call.
   if (continue_timer_target_time_ > base::Time::Now())
     return;
 
   continue_timer_started_ = false;
   host_->PauseSession(true);
   ShowContinueWindow(true);
 }
 
 
 }  // namespace remoting