Enforce canCopyWithMemcpy constraint over TerminatedArray<T>.

third_party/WebKit/Source/wtf/TerminatedArray.h

 // Copyright 2014 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 TerminatedArray_h
 #define TerminatedArray_h
 
 #include "wtf/Allocator.h"
 #include "wtf/PtrUtil.h"
+#include "wtf/VectorTraits.h"
 #include "wtf/allocator/Partitions.h"
 #include <memory>
 
 namespace WTF {
 
 // TerminatedArray<T> represents a sequence of elements of type T in which each
 // element knows whether it is the last element in the sequence or not. For this
 // check type T must provide isLastInArray method.
 // TerminatedArray<T> can only be constructed by TerminatedArrayBuilder<T>.
 template <typename T>
 class TerminatedArray {
   DISALLOW_NEW();
   WTF_MAKE_NONCOPYABLE(TerminatedArray);
 
  public:
+  // When TerminatedArray::Allocator implementations grow the backing
+  // store, old is copied into the new and larger block.
+  static_assert(VectorTraits<T>::canCopyWithMemcpy,
+                "Array elements must be memory copyable");
+
   T& at(size_t index) { return reinterpret_cast<T*>(this)[index]; }
   const T& at(size_t index) const {
     return reinterpret_cast<const T*>(this)[index];
   }
 
   template <typename U>
   class iterator_base final {
     STACK_ALLOCATED();
 
    public:
@@ skipping 74 matching lines @@
 
   template <typename, template <typename> class>
   friend class TerminatedArrayBuilder;
 };
 
 }  // namespace WTF
 
 using WTF::TerminatedArray;
 
 #endif  // TerminatedArray_h