Migrate WTF::HashMap::get() to ::at()

third_party/WebKit/Source/modules/peerconnection/RTCLegacyStatsReport.h

 /*
  * 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:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 28 matching lines @@
   DEFINE_WRAPPERTYPEINFO();
 
  public:
   static RTCLegacyStatsReport* create(const String& id,
                                       const String& type,
                                       double timestamp);
 
   double timestamp() const { return m_timestamp; }
   String id() { return m_id; }
   String type() { return m_type; }
-  String stat(const String& name) { return m_stats.get(name); }
+  String stat(const String& name) { return m_stats.at(name); }
   Vector<String> names() const;
 
   void addStatistic(const String& name, const String& value);
 
   DEFINE_INLINE_TRACE() {}
 
  private:
   RTCLegacyStatsReport(const String& id, const String& type, double timestamp);
 
   String m_id;
   String m_type;
   double m_timestamp;
   HashMap<String, String> m_stats;
 };
 
 }  // namespace blink
 
 #endif  // RTCLegacyStatsReport_h