LinkedStack.h is no longer used, remove it

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

 /*
  * Copyright (C) 2014 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 19 matching lines @@
 
 #ifndef HeapLinkedStack_h
 #define HeapLinkedStack_h
 
 #include "platform/heap/Heap.h"
 #include "platform/heap/Visitor.h"
 #include "wtf/Allocator.h"
 
 namespace blink {
 
+// HeapLinkedStack<> is an Oilpan-managed stack that avoids pre-allocation
+// of memory and heap fragmentation.
+//
+// The API was originally implemented on the call stack by LinkedStack<>
+// (now removed: https://codereview.chromium.org/2761853003/).
+// See https://codereview.chromium.org/17314010 for the original use-case.
 template <typename T>
 class HeapLinkedStack : public GarbageCollected<HeapLinkedStack<T>> {
  public:
   HeapLinkedStack() : m_size(0) {}
 
   bool isEmpty();
 
   void push(const T&);
   const T& peek();
   void pop();
@@ skipping 56 matching lines @@
 class TraceEagerlyTrait<HeapLinkedStack<T>> {
   STATIC_ONLY(TraceEagerlyTrait);
 
  public:
   static const bool value = TraceEagerlyTrait<T>::value;
 };
 
 }  // namespace blink
 
 #endif  // HeapLinkedStack_h