Do not clear mirror cache when fetching loaded scripts.

test/mjsunit/debug-mirror-cache.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 44 matching lines @@
     assertEquals(0, debug.mirror_cache_.length, "Mirror cache not cleared");
 
     // Get the debug command processor in paused state.
     var dcp = exec_state.debugCommandProcessor(false);
 
     // Make a backtrace request to create some mirrors.
     var json;
     json = '{"seq":0,"type":"request","command":"backtrace"}'
     dcp.processDebugJSONRequest(json);
 
+    // Make sure looking up loaded scripts does not clear the cache.
+    Debug.scripts();
+
     // Some mirrors where cached.
     assertFalse(debug.next_handle_ == 0, "Mirror cache not used");
     assertFalse(debug.mirror_cache_.length == 0, "Mirror cache not used");
   }
   } catch (e) {
     print(e);
     listenerExceptions.push(e);
   };
 };
 
 // Add the debug event listener.
 Debug.setListener(listener);
 
 // Enter the debugger twice.
 debugger;
 debugger;
 
 assertEquals([], listenerExceptions, "Exception in listener");
 // Make sure that the debug event listener vas invoked.
 assertEquals(2, listenerCallCount, "Listener not called");