WTF: Fix Vector<T> memcpy'ing incorrectly for some T.

third_party/WebKit/Source/wtf/VectorTest.cpp

 /*
  * Copyright (C) 2011 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 441 matching lines @@
     // the input reference stale).
     size_t limit = vector.capacity() + 1;
     for (size_t i = 0; i < limit; i++)
         vector.append(vector.first());
 
     limit = vector.capacity() + 1;
     for (size_t i = 0; i < limit; i++)
         vector.append(const_cast<const WTF::String&>(vector.first()));
 }
 
+// The test below is for the following issue:
+//
+// https://bugs.chromium.org/p/chromium/issues/detail?id=592767
+//
+// where deleted copy assignment operator made canMoveWithMemcpy true because of the implementation of
+// IsTriviallyMoveAssignable<T>.
+
+class MojoMoveOnlyType final {

[yzshen1, 2016/03/08 21:30:38]

Nit: this class itself doesn't have anything to do with Mojo. Maybe just name it
MoveOnlyType, or CopyDeletedType?

+public:
+    MojoMoveOnlyType();
+    MojoMoveOnlyType(MojoMoveOnlyType&&);
+    MojoMoveOnlyType& operator=(MojoMoveOnlyType&&);
+    ~MojoMoveOnlyType();
+
+private:
+    MojoMoveOnlyType(const MojoMoveOnlyType&) = delete;
+    void operator=(const MojoMoveOnlyType&) = delete;
+};
+
+static_assert(!IsTriviallyMoveAssignable<MojoMoveOnlyType>::value, "MojoMoveOnlyType isn't trivially move assignable.");
+static_assert(!IsTriviallyCopyAssignable<MojoMoveOnlyType>::value, "MojoMoveOnlyType isn't trivially copy assignable.");
+
+static_assert(!VectorTraits<MojoMoveOnlyType>::canMoveWithMemcpy, "MojoMoveOnlyType can't be moved with memcpy.");
+static_assert(!VectorTraits<MojoMoveOnlyType>::canCopyWithMemcpy, "MojoMoveOnlyType can't be copied with memcpy.");
+
 } // anonymous namespace
 
 } // namespace WTF