Implement callback when script finishes running in V8 API.

src/execution.cc

 // Copyright 2011 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 89 matching lines @@
 
   // Make sure that the global object of the context we're about to
   // make the current one is indeed a global object.
   ASSERT(function->context()->global()->IsGlobalObject());
 
   {
     // Save and restore context around invocation and block the
     // allocation of handles without explicit handle scopes.
     SaveContext save(isolate);
     NoHandleAllocation na;
+    // Increase call depth and fire callbacks after the call if applicable.
     JSEntryFunction stub_entry = FUNCTION_CAST<JSEntryFunction>(code->entry());
 
     // Call the function through the right JS entry stub.
     byte* function_entry = function->code()->entry();
     JSFunction* func = *function;
     Object* recv = *receiver;
     Object*** argv = reinterpret_cast<Object***>(args);
     value =
         CALL_GENERATED_CODE(stub_entry, function_entry, func, recv, argc, argv);
   }
@@ skipping 778 matching lines @@
     return isolate->TerminateExecution();
   }
   if (stack_guard->IsInterrupted()) {
     stack_guard->Continue(INTERRUPT);
     return isolate->StackOverflow();
   }
   return isolate->heap()->undefined_value();
 }
 
 } }  // namespace v8::internal