Devirtualize several inspector classes destructors

Source/core/inspector/InspectorHistory.cpp

 /*
  * Copyright (C) 2012 Google Inc. 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
@@ skipping 65 matching lines @@
 {
     return "";
 }
 
 void InspectorHistory::Action::merge(PassOwnPtr<Action>)
 {
 }
 
 InspectorHistory::InspectorHistory() : m_afterLastActionIndex(0) { }
 
-InspectorHistory::~InspectorHistory() { }
-
 bool InspectorHistory::perform(PassOwnPtr<Action> action, ExceptionState& es)
 {
     if (!action->perform(es))
         return false;
 
     if (!action->mergeId().isEmpty() && m_afterLastActionIndex > 0 && action->mergeId() == m_history[m_afterLastActionIndex - 1]->mergeId())
         m_history[m_afterLastActionIndex - 1]->merge(action);
     else {
         m_history.resize(m_afterLastActionIndex);
         m_history.append(action);
@@ skipping 45 matching lines @@
 }
 
 void InspectorHistory::reset()
 {
     m_afterLastActionIndex = 0;
     m_history.clear();
 }
 
 } // namespace WebCore