Oilpan: Remove unused swap methods for on-heap collections

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/Assertions.h"
@@ skipping 413 matching lines @@
     {
     }
 
     template<typename U>
     void append(const U& other)
     {
         Deque<T, inlineCapacity, HeapAllocator>::append(other);
     }
 };
 
-template<typename T, size_t i>
-inline void swap(HeapVector<T, i>& a, HeapVector<T, i>& b) { a.swap(b); }
-template<typename T, size_t i>
-inline void swap(HeapDeque<T, i>& a, HeapDeque<T, i>& b) { a.swap(b); }
-template<typename T, typename U, typename V>
-inline void swap(HeapHashSet<T, U, V>& a, HeapHashSet<T, U, V>& b) { a.swap(b); }
-template<typename T, typename U, typename V, typename W, typename X>
-inline void swap(HeapHashMap<T, U, V, W, X>& a, HeapHashMap<T, U, V, W, X>& b) { a.swap(b); }
-template<typename T, size_t i, typename U>
-inline void swap(HeapListHashSet<T, i, U>& a, HeapListHashSet<T, i, U>& b) { a.swap(b); }
-template<typename T, typename U, typename V>
-inline void swap(HeapLinkedHashSet<T, U, V>& a, HeapLinkedHashSet<T, U, V>& b) { a.swap(b); }
-template<typename T, typename U, typename V>
-inline void swap(HeapHashCountedSet<T, U, V>& a, HeapHashCountedSet<T, U, V>& b) { a.swap(b); }
-
 } // namespace blink
 
 #endif