Provide actual breakpoints locations in response to setBreakpoint and listBreakpoints requests.

src/runtime.cc

 // Copyright 2006-2009 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 9045 matching lines @@
   ASSERT(args.length() == 3);
   CONVERT_ARG_CHECKED(JSFunction, fun, 0);
   Handle<SharedFunctionInfo> shared(fun->shared());
   CONVERT_NUMBER_CHECKED(int32_t, source_position, Int32, args[1]);
   RUNTIME_ASSERT(source_position >= 0);
   Handle<Object> break_point_object_arg = args.at<Object>(2);
 
   // Set break point.
   Debug::SetBreakPoint(shared, break_point_object_arg, &source_position);
 
-  return Heap::undefined_value();
+  return Smi::FromInt(source_position);
 }
 
 
 Object* Runtime::FindSharedFunctionInfoInScript(Handle<Script> script,
                                                 int position) {
   // Iterate the heap looking for SharedFunctionInfo generated from the
   // script. The inner most SharedFunctionInfo containing the source position
   // for the requested break point is found.
   // NOTE: This might reqire several heap iterations. If the SharedFunctionInfo
   // which is found is not compiled it is compiled and the heap is iterated
@@ skipping 1302 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal