Remove unnecessary MemberHash<> templates.

third_party/WebKit/Source/platform/heap/Member.h

 // Copyright 2016 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 Member_h
 #define Member_h
 
 #include "wtf/Allocator.h"
 #include "wtf/HashFunctions.h"
 
@@ skipping 254 matching lines @@
     {
         this->m_raw = nullptr;
         return *this;
     }
 };
 
 } // namespace blink
 
 namespace WTF {
 
+// PtrHash is the default hash for hash tables with Member<>-derived elements.
 template <typename T>
 struct MemberHash : PtrHash<T> {
     STATIC_ONLY(MemberHash);
     template <typename U>
     static unsigned hash(const U& key) { return PtrHash<T>::hash(key); }
     template <typename U, typename V>
     static bool equal(const U& a, const V& b) { return a == b; }
 };
 
 template <typename T>
-struct WeakMemberHash : MemberHash<T> {
-    STATIC_ONLY(WeakMemberHash);
-};
-
-template <typename T>
-struct UntracedMemberHash : MemberHash<T> {
-    STATIC_ONLY(UntracedMemberHash);
-};
-
-// PtrHash is the default hash for hash tables with members.
-template <typename T>
 struct DefaultHash<blink::Member<T>> {
     STATIC_ONLY(DefaultHash);
     using Hash = MemberHash<T>;
 };
 
 template <typename T>
 struct DefaultHash<blink::WeakMember<T>> {
     STATIC_ONLY(DefaultHash);
-    using Hash = WeakMemberHash<T>;
+    using Hash = MemberHash<T>;
 };
 
 template <typename T>
 struct DefaultHash<blink::UntracedMember<T>> {
     STATIC_ONLY(DefaultHash);
-    using Hash = UntracedMemberHash<T>;
+    using Hash = MemberHash<T>;
 };
 
 template<typename T>
 struct IsTraceable<blink::Member<T>> {
     STATIC_ONLY(IsTraceable);
     static const bool value = true;
 };
 
 template<typename T>
 struct IsWeak<blink::WeakMember<T>> {
     STATIC_ONLY(IsWeak);
     static const bool value = true;
 };
 
 template<typename T>
 struct IsTraceable<blink::WeakMember<T>> {
     STATIC_ONLY(IsTraceable);
     static const bool value = true;
 };
 
 } // namespace WTF
 
 #endif // Member_h