Simpler return value of HashTable::add/HashMap:add and others

Source/core/inspector/InspectorTimelineAgent.cpp

 /*
 * Copyright (C) 2013 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 1173 matching lines @@
         m_platformInstrumentationClientInstalledAtStackDepth = m_recordStack.size();
         PlatformInstrumentation::setClient(this);
     }
 }
 
 TimelineThreadState& InspectorTimelineAgent::threadState(ThreadIdentifier thread)
 {
     ThreadStateMap::iterator it = m_threadStates.find(thread);
     if (it != m_threadStates.end())
         return it->value;
-    return m_threadStates.add(thread, TimelineThreadState(this)).iterator->value;
+    return m_threadStates.add(thread, TimelineThreadState(this)).storedValue->value;
 }
 
 void InspectorTimelineAgent::commitFrameRecord()
 {
     if (!m_pendingFrameRecord)
         return;
     innerAddRecordToTimeline(m_pendingFrameRecord.release());
 }
 
 void InspectorTimelineAgent::clearRecordStack()
@@ skipping 85 matching lines @@
 
 #ifndef NDEBUG
 bool TimelineRecordStack::isOpenRecordOfType(const String& type)
 {
     return !m_stack.isEmpty() && m_stack.last().type == type;
 }
 #endif
 
 } // namespace WebCore