heap: Remove SameThreadCheckedMember

SameThreadCheckedMember is never used and just adds complexity to
the codebase

Bug: 986235
Change-Id: I3f7e870c6a6ebdfc9a312531636573c0042f4074
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1899620Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712559}

third_party/blink/renderer/platform/heap/heap_allocator.h

@@ -736,17 +736,6 @@ struct VectorTraits<blink::Member<T>> : VectorTraitsBase<blink::Member<T>> {
   static const bool kCanMoveWithMemcpy = true;
 };
 
-template <typename T>
-struct VectorTraits<blink::SameThreadCheckedMember<T>>
-    : VectorTraitsBase<blink::SameThreadCheckedMember<T>> {
-  STATIC_ONLY(VectorTraits);
-  static const bool kNeedsDestruction = false;
-  static const bool kCanInitializeWithMemset = true;
-  static const bool kCanClearUnusedSlotsWithMemset = true;
-  static const bool kCanMoveWithMemcpy = true;
-  static const bool kCanSwapUsingCopyOrMove = false;
-};
-
 template <typename T>
 struct VectorTraits<blink::WeakMember<T>>
     : VectorTraitsBase<blink::WeakMember<T>> {
@@ -846,42 +835,6 @@ struct HashTraits<blink::Member<T>> : SimpleClassHashTraits<blink::Member<T>> {
   }
 };
 
-template <typename T>
-struct HashTraits<blink::SameThreadCheckedMember<T>>
-    : SimpleClassHashTraits<blink::SameThreadCheckedMember<T>> {
-  STATIC_ONLY(HashTraits);
-  // FIXME: Implement proper const'ness for iterator types. Requires support
-  // in the marking Visitor.
-  using PeekInType = T*;
-  using IteratorGetType = blink::SameThreadCheckedMember<T>*;
-  using IteratorConstGetType = const blink::SameThreadCheckedMember<T>*;
-  using IteratorReferenceType = blink::SameThreadCheckedMember<T>&;
-  using IteratorConstReferenceType = const blink::SameThreadCheckedMember<T>&;
-  static IteratorReferenceType GetToReferenceConversion(IteratorGetType x) {
-    return *x;
-  }
-  static IteratorConstReferenceType GetToReferenceConstConversion(
-      IteratorConstGetType x) {
-    return *x;
-  }
-
-  using PeekOutType = T*;
-
-  template <typename U>
-  static void Store(const U& value,
-                    blink::SameThreadCheckedMember<T>& storage) {
-    storage = value;
-  }
-
-  static PeekOutType Peek(const blink::SameThreadCheckedMember<T>& value) {
-    return value;
-  }
-
-  static blink::SameThreadCheckedMember<T> EmptyValue() {
-    return blink::SameThreadCheckedMember<T>(nullptr, nullptr);
-  }
-};
-
 template <typename T>
 struct HashTraits<blink::WeakMember<T>>
     : SimpleClassHashTraits<blink::WeakMember<T>> {

third_party/blink/renderer/platform/heap/member.h

@@ -326,99 +326,6 @@ class Member : public MemberBase<T, TracenessMemberConfiguration::kTraced> {
   friend class WTF::ConstructTraits;
 };
 
-// A checked version of Member<>, verifying that only same-thread references
-// are kept in the smart pointer. Intended to be used to diagnose unclean
-// thread reference usage in release builds. It simply exposes the debug-only
-// MemberBase<> checking we already have in place for select usage to diagnose
-// per-thread issues. Only intended used temporarily while diagnosing suspected
-// problems with cross-thread references.
-template <typename T>
-class SameThreadCheckedMember : public Member<T> {
-  DISALLOW_NEW();
-  typedef Member<T> Parent;
-
- public:
-  SameThreadCheckedMember() : Parent() { SaveCreationThreadState(); }
-  SameThreadCheckedMember(std::nullptr_t) : Parent(nullptr) {
-    SaveCreationThreadState();
-  }
-
-  SameThreadCheckedMember(T* raw) : Parent(raw) {
-    SaveCreationThreadState();
-    CheckPointer();
-  }
-
-  SameThreadCheckedMember(T& raw) : Parent(raw) {
-    SaveCreationThreadState();
-    CheckPointer();
-  }
-
-  SameThreadCheckedMember(WTF::HashTableDeletedValueType x) : Parent(x) {
-    SaveCreationThreadState();
-    CheckPointer();
-  }
-
-  SameThreadCheckedMember(const SameThreadCheckedMember& other)
-      : Parent(other) {
-    SaveCreationThreadState();
-  }
-  template <typename U>
-  SameThreadCheckedMember(const SameThreadCheckedMember<U>& other)
-      : Parent(other) {
-    SaveCreationThreadState();
-    CheckPointer();
-  }
-
-  template <typename U>
-  SameThreadCheckedMember(const Persistent<U>& other) : Parent(other) {
-    SaveCreationThreadState();
-    CheckPointer();
-  }
-
-  template <typename U>
-  SameThreadCheckedMember& operator=(const Persistent<U>& other) {
-    Parent::operator=(other);
-    CheckPointer();
-    return *this;
-  }
-
-  template <typename U>
-  SameThreadCheckedMember& operator=(const SameThreadCheckedMember<U>& other) {
-    Parent::operator=(other);
-    CheckPointer();
-    return *this;
-  }
-
-  template <typename U>
-  SameThreadCheckedMember& operator=(const WeakMember<U>& other) {
-    Parent::operator=(other);
-    CheckPointer();
-    return *this;
-  }
-
-  template <typename U>
-  SameThreadCheckedMember& operator=(U* other) {
-    Parent::operator=(other);
-    CheckPointer();
-    return *this;
-  }
-
-  SameThreadCheckedMember& operator=(std::nullptr_t) {
-    Parent::operator=(nullptr);
-    return *this;
-  }
-
- private:
-  void CheckPointer() { pointer_verifier_.CheckPointer(this->GetRaw()); }
-
-  void SaveCreationThreadState() {
-    pointer_verifier_.SaveCreationThreadState(this->GetRaw());
-  }
-
-  MemberPointerVerifier<T, TracenessMemberConfiguration::kTraced>
-      pointer_verifier_;
-};
-
 // WeakMember is similar to Member in that it is used to point to other oilpan
 // heap allocated objects.
 // However instead of creating a strong pointer to the object, the WeakMember
@@ -560,12 +467,6 @@ struct DefaultHash<blink::UntracedMember<T>> {
   using Hash = MemberHash<T>;
 };
 
-template <typename T>
-struct DefaultHash<blink::SameThreadCheckedMember<T>> {
-  STATIC_ONLY(DefaultHash);
-  using Hash = MemberHash<T>;
-};
-
 template <typename T>
 struct IsTraceable<blink::Member<T>> {
   STATIC_ONLY(IsTraceable);
@@ -584,12 +485,6 @@ struct IsTraceable<blink::WeakMember<T>> {
   static const bool value = true;
 };
 
-template <typename T>
-struct IsTraceable<blink::SameThreadCheckedMember<T>> {
-  STATIC_ONLY(IsTraceable);
-  static const bool value = true;
-};
-
 template <typename T, typename Traits, typename Allocator>
 class ConstructTraits<blink::Member<T>, Traits, Allocator> {
   STATIC_ONLY(ConstructTraits);

third_party/blink/renderer/platform/heap/threading_traits.h

@@ -16,9 +16,6 @@
 
 namespace blink {
 
-template <typename T>
-class SameThreadCheckedMember;
-
 // ThreadAffinity indicates which threads objects can be used on. We
 // distinguish between objects that can be used on the main thread
 // only and objects that can be used on any thread.
@@ -83,12 +80,6 @@ struct ThreadingTrait<Member<T>> {
   static const ThreadAffinity kAffinity = ThreadingTrait<T>::kAffinity;
 };
 
-template <typename T>
-struct ThreadingTrait<SameThreadCheckedMember<T>> {
-  STATIC_ONLY(ThreadingTrait);
-  static const ThreadAffinity kAffinity = ThreadingTrait<T>::Affinity;
-};
-
 template <typename T>
 struct ThreadingTrait<WeakMember<T>> {
   STATIC_ONLY(ThreadingTrait);

third_party/blink/renderer/platform/heap/visitor.h

@@ -57,8 +57,6 @@ struct TraceTrait;
 class ThreadState;
 class Visitor;
 template <typename T>
-class SameThreadCheckedMember;
-template <typename T>
 class TraceWrapperV8Reference;
 
 // The TraceMethodDelegate is used to convert a trace method for type T to a
@@ -107,11 +105,6 @@ class PLATFORM_EXPORT Visitor {
     Trace(t.GetSafe());
   }
 
-  template <typename T>
-  void Trace(const SameThreadCheckedMember<T>& t) {
-    Trace(static_cast<const Member<T>&>(t));
-  }
-
   // Fallback methods used only when we need to trace raw pointers of T. This is
   // the case when a member is a union where we do not support members.
   template <typename T>