PPAPI: Make PPB_MessageLoop_Dev::GetForMainThread work

ppapi/proxy/plugin_globals.h

 // Copyright (c) 2012 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 PPAPI_PROXY_PLUGIN_GLOBALS_H_
 #define PPAPI_PROXY_PLUGIN_GLOBALS_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_local_storage.h"
 #include "ppapi/proxy/plugin_resource_tracker.h"
 #include "ppapi/proxy/plugin_var_tracker.h"
 #include "ppapi/proxy/ppapi_proxy_export.h"
 #include "ppapi/shared_impl/callback_tracker.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
 
 namespace ppapi {
 namespace proxy {
 
+class MessageLoopResource;
 class PluginProxyDelegate;
 
 class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
  public:
   PluginGlobals();
   PluginGlobals(PpapiGlobals::ForTest);
   virtual ~PluginGlobals();
 
   // Getter for the global singleton. Generally, you should use
   // PpapiGlobals::Get() when possible. Use this only when you need some
@@ skipping 48 matching lines @@
   base::ThreadLocalStorage::Slot* msg_loop_slot() {
     return msg_loop_slot_.get();
   }
 
   // Sets the message loop slot, takes ownership of the given heap-alloated
   // pointer.
   void set_msg_loop_slot(base::ThreadLocalStorage::Slot* slot) {
     msg_loop_slot_.reset(slot);
   }
 
+  // Return the special Resource that represents the MessageLoop for the main
+  // thread. This Resource is not associated with any instance, and lives as
+  // long as the plugin.
+  MessageLoopResource* loop_for_main_thread();
+
   // The embedder should call this function when the name of the plugin module
   // is known. This will be used for error logging.
   void set_plugin_name(const std::string& name) { plugin_name_ = name; }
 
   // The embedder should call this function when the command line is known.
   void set_command_line(const std::string& c) { command_line_ = c; }
 
  private:
   // PpapiGlobals overrides.
   virtual bool IsPluginGlobals() const OVERRIDE;
 
   static PluginGlobals* plugin_globals_;
 
   PluginProxyDelegate* plugin_proxy_delegate_;
   PluginResourceTracker plugin_resource_tracker_;
   PluginVarTracker plugin_var_tracker_;
   scoped_refptr<CallbackTracker> callback_tracker_;
   base::Lock proxy_lock_;
 
   scoped_ptr<base::ThreadLocalStorage::Slot> msg_loop_slot_;
+  // Note that loop_for_main_thread's constructor sets msg_loop_slot_, so it
+  // must be initialized after msg_loop_slot_ (hence the order here).
+  scoped_refptr<MessageLoopResource> loop_for_main_thread_;
 
   // Name of the plugin used for error logging. This will be empty until
   // set_plugin_name is called.
   std::string plugin_name_;
 
   // Command line for the plugin. This will be empty until set_command_line is
   // called.
   std::string command_line_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginGlobals);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif   // PPAPI_PROXY_PLUGIN_GLOBALS_H_