Revert of Avoid argument copying in WTF hash-based containers

Source/wtf/HashMapTest.cpp

Index: Source/wtf/HashMapTest.cpp
diff --git a/Source/wtf/HashMapTest.cpp b/Source/wtf/HashMapTest.cpp
index 931ec737b33d439e27bc0374558d4e8b4667035a..cbdbca6eb6c1c11b65ad3537b508e6267e0067ea 100644
--- a/Source/wtf/HashMapTest.cpp
+++ b/Source/wtf/HashMapTest.cpp
@@ -303,62 +303,6 @@
     EXPECT_EQ(0, InstanceCounter::counter);
 }
 
-class CopyCounter {
-public:
-    CopyCounter() = default;
-    explicit CopyCounter(int data) : m_data(data) { }
-
-    CopyCounter(const CopyCounter& copy) : m_data(copy.m_data) { ++s_counter; }
-
-    int data() const { return m_data; }
-
-    bool isHashTableDeletedValue() const { return m_data == HashTableDeletedValue; }
-
-    static int s_counter;
-private:
-    int m_data;
-};
-
-int CopyCounter::s_counter = 0;
-
-struct CopyCounterHash {
-    static unsigned hash(const CopyCounter& key)
-    {
-        return IntHash<unsigned>::hash(key.data());
-    }
-
-    static bool equal(const CopyCounter& a, const CopyCounter& b)
-    {
-        return a.data() == b.data();
-    }
-
-    static const bool safeToCompareToEmptyOrDeleted = true;
-};
-
-struct CopyCounterHashTraits: SimpleClassHashTraits<CopyCounter> {
-#if COMPILER(MSVC)
-    // Need this in order to enable RVO on VS2013 (the default traits
-    // implementation would produce an unneeded copy).
-    static CopyCounter emptyValue()
-    {
-        CopyCounter empty;
-        return empty;
-    }
-#endif
-    static const bool hasIsEmptyValueFunction = true;
-    static bool isEmptyValue(const CopyCounter& counter) { return !counter.data(); }
-};
-
-TEST(HashMapTest, LookupNoKeyCopies)
-{
-    HashMap<CopyCounter, int, CopyCounterHash, CopyCounterHashTraits> map;
-
-    map.contains(CopyCounter(1));
-    auto it = map.find(CopyCounter(1));
-    ALLOW_UNUSED_LOCAL(it);
-    EXPECT_EQ(0, CopyCounter::s_counter);
-}
-
 } // anonymous namespace
 
 } // namespace WTF