Revert 106677 (caused several PPAPI test timeouts, see http://crbug.com/101154)

ppapi/proxy/dispatcher.h

Index: ppapi/proxy/dispatcher.h
===================================================================
--- ppapi/proxy/dispatcher.h	(revision 106716)
+++ ppapi/proxy/dispatcher.h	(working copy)
@@ -14,6 +14,7 @@
 #include "ipc/ipc_channel_proxy.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_module.h"
+#include "ppapi/proxy/callback_tracker.h"
 #include "ppapi/proxy/proxy_channel.h"
 #include "ppapi/proxy/interface_list.h"
 #include "ppapi/proxy/interface_proxy.h"
@@ -82,6 +83,10 @@
   // IPC::Channel::Listener implementation.
   virtual bool OnMessageReceived(const IPC::Message& msg);
 
+  CallbackTracker& callback_tracker() {
+    return callback_tracker_;
+  }
+
   GetInterfaceFunc local_get_interface() const { return local_get_interface_; }
 
  protected:
@@ -111,6 +116,8 @@
 
   GetInterfaceFunc local_get_interface_;
 
+  CallbackTracker callback_tracker_;
+
   scoped_ptr<VarSerializationRules> serialization_rules_;
 
   DISALLOW_COPY_AND_ASSIGN(Dispatcher);