Make sure we don't keep tab id - handles mapping when a dread dies....

ceee/ie/broker/executors_manager.h

Index: ceee/ie/broker/executors_manager.h
===================================================================
--- ceee/ie/broker/executors_manager.h	(revision 68024)
+++ ceee/ie/broker/executors_manager.h	(working copy)
@@ -16,6 +16,7 @@
 
 #include "base/lock.h"
 #include "base/singleton.h"
+#include "base/task.h"
 #include "ceee/common/window_utils.h"
 #include "ceee/ie/broker/window_events_funnel.h"
 
@@ -120,6 +121,10 @@
   // Unregister the HWND and its corresponding tab ID and tool band tab ID.
   virtual void DeleteTabHandle(HWND handle);
 
+  // Cleans up the maps from all handles that would be associated to the given
+  // thread id.
+  virtual void CleanupMapsForThread(DWORD thread_id);
+
   // Traits for Singleton<ExecutorsManager> so that we can pass an argument
   // to the constructor.
   struct SingletonTraits : public DefaultSingletonTraits<ExecutorsManager> {