Changed the debugger API to allow only one debug event listener to be registe...

test/mjsunit/debug-backtrace-text.js

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 84 matching lines @@
       assertEquals("[anonymous]()", exec_state.frame(2).invocationText());
       listenerCalled = true;
     }
   }
   } catch (e) {
     exception = e
   };
 };
 
 // Add the debug event listener.
-Debug.addListener(listener);
+Debug.setListener(listener);
 
 // Set a break point and call to invoke the debug event listener.
 a[2](p1, p2)
 
 // Make sure that the debug event listener vas invoked.
 assertTrue(listenerCalled);
 assertFalse(exception, "exception in listener")
 
 // Set a break point and call to invoke the debug event listener.
 listenerCalled = false;
 testConstructor = true;
 Debug.setBreakPoint(Point, 0, 0);
 createPoint(0, 0);
 
 // Make sure that the debug event listener vas invoked (again).
 assertTrue(listenerCalled);
 assertFalse(exception, "exception in listener")