Remove C::swap(C*) where C = Hash{Map,Set}<T>.

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

 // Copyright 2015 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 HeapAllocator_h
 #define HeapAllocator_h
 
 #include "platform/heap/Heap.h"
 #include "platform/heap/TraceTraits.h"
 #include "wtf/Allocator.h"
@@ skipping 132 matching lines @@
     }
 
 #if ENABLE(ASSERT)
     template<typename VisitorDispatcher>
     static bool weakTableRegistered(VisitorDispatcher visitor, const void* closure)
     {
         return visitor->weakTableRegistered(closure);
     }
 #endif
 
-    template<typename T>
-    struct ResultType {
-        using Type = T*;
-    };
-
-    template<typename T>
-    struct OtherType {
-        using Type = T*;
-    };
-
-    template<typename T>
-    static T& getOther(T* other)
-    {
-        return *other;
-    }
-
     static void enterGCForbiddenScope()
     {
         ThreadState::current()->enterGCForbiddenScope();
     }
 
     static void leaveGCForbiddenScope()
     {
         ThreadState::current()->leaveGCForbiddenScope();
     }
 
@@ skipping 389 matching lines @@
     static_assert(sizeof(T), "T must be fully defined");
     // All heap allocated node pointers need visiting to keep the nodes alive,
     // regardless of whether they contain pointers to other heap allocated
     // objects.
     static const bool value = true;
 };
 
 } // namespace WTF
 
 #endif