Make HeapObjectHeader::checkHeader private.

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), m_parent(parent) {
 #if DCHECK_IS_ON()
     if (m_parent) {
-      HeapObjectHeader::fromPayload(m_parent)->checkHeader();
+      // |fromPayload| checks the integrity of the |HeapObjectHeader|.
+      (void)HeapObjectHeader::fromPayload(m_parent);

[haraken, 2017/03/30 14:12:46]

I'd prefer having HeapObjectHeader::checkHeader() instead of using (void)
though.

     }
 #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.
@@ skipping 97 matching lines @@
   b.clear();
   b.reserveCapacity(temp.size());
   for (auto item : temp) {
     b.push_back(item.get());
   }
 }
 
 }  // namespace blink
 
 #endif  // TraceWrapperMember_h