Add PluginMessageLoopProxy and use it for Host plugin UI thread.

remoting/host/plugin/host_script_object.cc

Index: remoting/host/plugin/host_script_object.cc
diff --git a/remoting/host/plugin/host_script_object.cc b/remoting/host/plugin/host_script_object.cc
index 5357cfb65a59e5dc8f04c41ee3bc403709f88eac..7f714147dfea9a223e9b1fa6b7dd84c7d7d93702 100644
--- a/remoting/host/plugin/host_script_object.cc
+++ b/remoting/host/plugin/host_script_object.cc
@@ -75,13 +75,19 @@ static bool g_logging_to_plugin = false;
 static HostNPScriptObject* g_logging_scriptable_object = NULL;
 static logging::LogMessageHandlerFunction g_logging_old_handler = NULL;
 
-HostNPScriptObject::HostNPScriptObject(NPP plugin, NPObject* parent)
+HostNPScriptObject::HostNPScriptObject(
+    NPP plugin,
+    NPObject* parent,
+    PluginMessageLoopProxy::Delegate* plugin_thread_delegate)
     : plugin_(plugin),
       parent_(parent),
       state_(kDisconnected),
       log_debug_info_func_(NULL),
       on_state_changed_func_(NULL),
       np_thread_id_(base::PlatformThread::CurrentId()),
+      plugin_message_loop_proxy_(
+          new PluginMessageLoopProxy(plugin_thread_delegate)),
+      host_context_(plugin_message_loop_proxy_),
       failed_login_attempts_(0),
       disconnected_event_(true, false) {
   // Set up log message handler.
@@ -96,10 +102,6 @@ HostNPScriptObject::HostNPScriptObject(NPP plugin, NPObject* parent)
     g_logging_old_handler = logging::GetLogMessageHandler();
   logging::SetLogMessageHandler(&LogToUI);
   g_logging_scriptable_object = this;
-
-  VLOG(2) << "HostNPScriptObject";
-  host_context_.SetUITaskPostFunction(base::Bind(
-      &HostNPScriptObject::PostTaskToNPThread, base::Unretained(this)));
 }
 
 HostNPScriptObject::~HostNPScriptObject() {
@@ -113,11 +115,12 @@ HostNPScriptObject::~HostNPScriptObject() {
   g_logging_old_handler = NULL;
   g_logging_scriptable_object = NULL;
 
+  plugin_message_loop_proxy_->Detach();
+
   // Disconnect synchronously. We cannot disconnect asynchronously
   // here because |host_context_| needs to be stopped on the plugin
   // thread, but the plugin thread may not exist after the instance
   // is destroyed.
-  destructing_.Set();
   disconnected_event_.Reset();
   DisconnectInternal();
   disconnected_event_.Wait();
@@ -514,11 +517,8 @@ void HostNPScriptObject::OnReceivedSupportID(
 }
 
 void HostNPScriptObject::OnStateChanged(State state) {
-  if (destructing_.IsSet())
-    return;
-
-  if (!host_context_.IsUIThread()) {
-    host_context_.PostTaskToUIThread(
+  if (!plugin_message_loop_proxy_->BelongsToCurrentThread()) {
+    plugin_message_loop_proxy_->PostTask(
         FROM_HERE, base::Bind(&HostNPScriptObject::OnStateChanged,
                               base::Unretained(this), state));
     return;
@@ -552,11 +552,8 @@ bool HostNPScriptObject::LogToUI(int severity, const char* file, int line,
 }
 
 void HostNPScriptObject::LogDebugInfo(const std::string& message) {
-  if (destructing_.IsSet())
-    return;
-
-  if (!host_context_.IsUIThread()) {
-    host_context_.PostTaskToUIThread(
+  if (!plugin_message_loop_proxy_->BelongsToCurrentThread()) {
+    plugin_message_loop_proxy_->PostTask(
         FROM_HERE, base::Bind(&HostNPScriptObject::LogDebugInfo,
                               base::Unretained(this), message));
     return;
@@ -588,25 +585,4 @@ bool HostNPScriptObject::InvokeAndIgnoreResult(NPObject* func,
   return is_good;
 }
 
-void HostNPScriptObject::PostTaskToNPThread(
-    const tracked_objects::Location& from_here, const base::Closure& task) {
-  // The NPAPI functions cannot make use of |from_here|, but this method is
-  // passed as a callback to ChromotingHostContext, so it needs to have the
-  // appropriate signature.
-
-  // Copy task to the heap so that we can pass it to NPTaskSpringboard().
-  base::Closure* task_in_heap = new base::Closure(task);
-
-  // Can be called from any thread.
-  g_npnetscape_funcs->pluginthreadasynccall(plugin_, &NPTaskSpringboard,
-                                            task_in_heap);
-}
-
-// static
-void HostNPScriptObject::NPTaskSpringboard(void* task) {
-  base::Closure* real_task = reinterpret_cast<base::Closure*>(task);
-  real_task->Run();
-  delete real_task;
-}
-
 }  // namespace remoting