Revert 96981 - Add PluginMessageLoopProxy and use it for Host plugin UI thread.

remoting/host/plugin/host_script_object.h

Index: remoting/host/plugin/host_script_object.h
===================================================================
--- remoting/host/plugin/host_script_object.h	(revision 96983)
+++ remoting/host/plugin/host_script_object.h	(working copy)
@@ -15,7 +15,6 @@
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/platform_thread.h"
 #include "base/time.h"
-#include "remoting/base/plugin_message_loop_proxy.h"
 #include "remoting/host/chromoting_host_context.h"
 #include "remoting/host/host_status_observer.h"
 #include "remoting/host/plugin/host_plugin_utils.h"
@@ -46,8 +45,7 @@
 // destroyed it sychronously shuts down the host and all threads.
 class HostNPScriptObject : public HostStatusObserver {
  public:
-  HostNPScriptObject(NPP plugin, NPObject* parent,
-                     PluginMessageLoopProxy::Delegate* plugin_thread_delegate);
+  HostNPScriptObject(NPP plugin, NPObject* parent);
   virtual ~HostNPScriptObject();
 
   bool Init();
@@ -144,6 +142,13 @@
                              const NPVariant* args,
                              uint32_t argCount);
 
+  // Posts a task on the main NP thread.
+  void PostTaskToNPThread(
+      const tracked_objects::Location& from_here, const base::Closure& task);
+
+  // Utility function for PostTaskToNPThread.
+  static void NPTaskSpringboard(void* task);
+
   // Set an exception for the current call.
   void SetException(const std::string& exception_string);
 
@@ -157,7 +162,6 @@
   ScopedRefNPObject log_debug_info_func_;
   ScopedRefNPObject on_state_changed_func_;
   base::PlatformThreadId np_thread_id_;
-  scoped_refptr<PluginMessageLoopProxy> plugin_message_loop_proxy_;
 
   scoped_ptr<RegisterSupportHostRequest> register_request_;
   scoped_refptr<MutableHostConfig> host_config_;
@@ -168,6 +172,7 @@
   int failed_login_attempts_;
 
   base::WaitableEvent disconnected_event_;
+  base::CancellationFlag destructing_;
 
   scoped_ptr<policy_hack::NatPolicy> nat_policy_;