Ensure that PP_Instance values are unique within a plugin process in addition...

chrome/ppapi_plugin/ppapi_thread.h

Index: chrome/ppapi_plugin/ppapi_thread.h
===================================================================
--- chrome/ppapi_plugin/ppapi_thread.h	(revision 77663)
+++ chrome/ppapi_plugin/ppapi_thread.h	(working copy)
@@ -27,7 +27,8 @@
 }
 }
 
-class PpapiThread : public ChildThread {
+class PpapiThread : public ChildThread,
+                    public pp::proxy::Dispatcher::Delegate {
  public:
   PpapiThread();
   ~PpapiThread();
@@ -36,6 +37,11 @@
   // ChildThread overrides.
   virtual bool OnMessageReceived(const IPC::Message& msg);
 
+  // Dispatcher::Delegate implementation.
+  virtual MessageLoop* GetIPCMessageLoop();
+  virtual base::WaitableEvent* GetShutdownEvent();
+  virtual std::set<PP_Instance>* GetGloballySeenInstanceIDSet();
+
   // Message handlers.
   void OnMsgLoadPlugin(const FilePath& path);
   void OnMsgCreateChannel(base::ProcessHandle host_process_handle,
@@ -59,6 +65,9 @@
   // and pass it around as necessary.
   PP_Module local_pp_module_;
 
+  // See Dispatcher::Delegate::GetGloballySeenInstanceIDSet.
+  std::set<PP_Instance> globally_seen_instance_ids_;
+
   DISALLOW_COPY_AND_ASSIGN(PpapiThread);
 };