Move more files to platform/bindings

third_party/WebKit/Source/bindings/core/v8/TraceWrapperMember.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 TraceWrapperMember_h
-#define TraceWrapperMember_h
-
-#include "bindings/core/v8/ScriptWrappableVisitor.h"
-#include "platform/heap/HeapAllocator.h"
-
-namespace blink {
-
-class HeapObjectHeader;
-template <typename T>
-class Member;
-
-/**
- * TraceWrapperMember is used for Member fields that should participate in
- * wrapper tracing, i.e., strongly hold a ScriptWrappable alive. All
- * TraceWrapperMember fields must be traced in the class' traceWrappers method.
- */
-template <class T>
-class TraceWrapperMember : public Member<T> {
-  DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
-
- public:
-  TraceWrapperMember(void* parent, T* raw) : Member<T>(raw), parent_(parent) {
-#if DCHECK_IS_ON()
-    if (parent_) {
-      HeapObjectHeader::CheckFromPayload(parent_);
-    }
-#endif
-    // We don't require a write barrier here as TraceWrapperMember is used for
-    // the following scenarios:
-    // - Initial initialization: The write barrier will not fire as the parent
-    //   is initially white.
-    // - Wrapping when inserting into a container: The write barrier will fire
-    //   upon establishing the move into the container.
-    // - Assignment to a field: The regular assignment operator will fire the
-    //   write barrier.
-    // Note that support for black allocation would require a barrier here.
-  }
-  TraceWrapperMember(WTF::HashTableDeletedValueType x)
-      : Member<T>(x), parent_(nullptr) {}
-
-  /**
-   * Copying a TraceWrapperMember means that its backpointer will also be
-   * copied.
-   */
-  TraceWrapperMember(const TraceWrapperMember& other) { *this = other; }
-
-  TraceWrapperMember& operator=(const TraceWrapperMember& other) {
-    DCHECK(!other.raw_ || other.parent_);
-    parent_ = other.parent_;
-    Member<T>::operator=(other);
-    ScriptWrappableVisitor::WriteBarrier(parent_, other);
-    return *this;
-  }
-
-  TraceWrapperMember& operator=(const Member<T>& other) {
-    DCHECK(!TraceWrapperMemberIsNotInitialized());
-    Member<T>::operator=(other);
-    ScriptWrappableVisitor::WriteBarrier(parent_, other);
-    return *this;
-  }
-
-  TraceWrapperMember& operator=(T* other) {
-    DCHECK(!TraceWrapperMemberIsNotInitialized());
-    Member<T>::operator=(other);
-    ScriptWrappableVisitor::WriteBarrier(parent_, other);
-    return *this;
-  }
-
-  TraceWrapperMember& operator=(std::nullptr_t) {
-    // No need for a write barrier when assigning nullptr.
-    Member<T>::operator=(nullptr);
-    return *this;
-  }
-
-  void* Parent() { return parent_; }
-
- private:
-  bool TraceWrapperMemberIsNotInitialized() { return !parent_; }
-
-  /**
-   * The parent object holding strongly onto the actual Member.
-   */
-  void* parent_;
-};
-
-/**
- * Swaps two HeapVectors specialized for TraceWrapperMember. The custom swap
- * function is required as TraceWrapperMember contains ownership information
- * which is not copyable but has to be explicitly specified.
- */
-template <typename T>
-void swap(HeapVector<TraceWrapperMember<T>>& a,
-          HeapVector<TraceWrapperMember<T>>& b,
-          void* parent_for_a,
-          void* parent_for_b) {
-  HeapVector<TraceWrapperMember<T>> temp;
-  temp.ReserveCapacity(a.size());
-  for (auto item : a) {
-    temp.push_back(TraceWrapperMember<T>(parent_for_b, item.Get()));
-  }
-  a.clear();
-  a.ReserveCapacity(b.size());
-  for (auto item : b) {
-    a.push_back(TraceWrapperMember<T>(parent_for_a, item.Get()));
-  }
-  b.clear();
-  b.ReserveCapacity(temp.size());
-  for (auto item : temp) {
-    b.push_back(TraceWrapperMember<T>(parent_for_b, item.Get()));
-  }
-}
-
-/**
- * Swaps two HeapVectors, one containing TraceWrapperMember and one with
- * regular Members. The custom swap function is required as
- * TraceWrapperMember contains ownership information which is not copyable
- * but has to be explicitly specified.
- */
-template <typename T>
-void swap(HeapVector<TraceWrapperMember<T>>& a,
-          HeapVector<Member<T>>& b,
-          void* parent_for_a) {
-  HeapVector<TraceWrapperMember<T>> temp;
-  temp.ReserveCapacity(a.size());
-  for (auto item : a) {
-    temp.push_back(TraceWrapperMember<T>(item.Parent(), item.Get()));
-  }
-  a.clear();
-  a.ReserveCapacity(b.size());
-  for (auto item : b) {
-    a.push_back(TraceWrapperMember<T>(parent_for_a, item.Get()));
-  }
-  b.clear();
-  b.ReserveCapacity(temp.size());
-  for (auto item : temp) {
-    b.push_back(item.Get());
-  }
-}
-
-}  // namespace blink
-
-#endif  // TraceWrapperMember_h
+// This file has been moved to platform/bindings/TraceWrapperMember.h.
+// TODO(adithyas): Remove this file.
+#include "platform/bindings/TraceWrapperMember.h"