[liveedit] reimplement frame restarting.

test/debugger/debug/debug-liveedit-replace-code.js

+// Copyright 2017 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.
+
+Debug = debug.Debug
+var counter = 0;
+var exception = null;
+
+function f() {
+  if (++counter > 5) return;
+  debugger;
+  return counter;
+}
+
+function listener(event, exec_state, event_data, data) {
+  if (event != Debug.DebugEvent.Break) return;
+  try {
+    var script = Debug.findScript(f);
+    var original = 'debugger;';
+    var patch = 'debugger;\n';
+    var position = script.source.indexOf(original);
+    Debug.LiveEdit.TestApi.ApplySingleChunkPatch(
+        script, position, original.length, patch, []);
+  } catch (e) {
+    exception = e;
+  }
+}
+
+Debug.setListener(listener);
+f();
+Debug.setListener(null);
+assertNull(exception);
+assertEquals(6, counter);