First version of PerformanceObserver

Source/core/inspector/AsyncOperationMap.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef AsyncOperationMap_h
 #define AsyncOperationMap_h
 
 #include "core/inspector/InspectorDebuggerAgent.h"
 #include "platform/heap/Handle.h"
 #include "wtf/HashMap.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefPtr.h"
 
 namespace blink {
 
-template <class K>
+template <class K, class MapType = WillBeHeapHashMap<K, int>>
 class AsyncOperationMap final {
     ALLOW_ONLY_INLINE_ALLOCATION();
 public:
-    using MapType = WillBeHeapHashMap<K, int>;
     explicit AsyncOperationMap(InspectorDebuggerAgent* debuggerAgent)
         : m_debuggerAgent(debuggerAgent)
     {
     }
 
     ~AsyncOperationMap()
     {
         // Verify that this object has been explicitly disposed.
         ASSERT(hasBeenDisposed());
     }
@@ skipping 50 matching lines @@
 
 private:
     RawPtrWillBeMember<InspectorDebuggerAgent> m_debuggerAgent;
     MapType m_asyncOperations;
 };
 
 } // namespace blink
 
 
 #endif // AsyncOperationMap_h