[debugger] Further stepping support in test wrapper

test/debugger/debugger/debug-step-2.js

-// Copyright 2016 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-const Debug = new DebugWrapper();
-Debug.enable();
-
-// This test tests that full code compiled without debug break slots
-// is recompiled with debug break slots when debugging is started.
-
-var bp;
-var done = false;
-var step_count = 0;
-
-// Debug event listener which steps until the global variable done is true.
-function listener(event, exec_state, event_data, data) {
-  if (event == Debug.DebugEvent.Break) {
-    if (!done) Debug.stepOver();
-    step_count++;
-  }
-};
-
-// Set the global variables state to prpare the stepping test.
-function prepare_step_test() {
-  done = false;
-  step_count = 0;
-}
-
-// Test function to step through.
-function f() {
-  var i = 1;
-  var j = 2;
-  done = true;
-};
-
-prepare_step_test();
-f();
-
-// Add the debug event listener.
-Debug.setListener(listener);
-
-bp = Debug.setBreakPoint(f, 1);
-
-prepare_step_test();
-f();
-assertEquals(4, step_count);
-Debug.clearBreakPoint(bp);
-
-// Set a breakpoint on the first var statement (line 1).
-bp = Debug.setBreakPoint(f, 1);
-
-// Step through the function ensuring that the var statements are hit as well.
-prepare_step_test();
-f();
-assertEquals(4, step_count);
-
-// Clear the breakpoint and check that no stepping happens.
-Debug.clearBreakPoint(bp);
-prepare_step_test();
-f();
-assertEquals(0, step_count);