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

third_party/WebKit/Source/wtf/VectorTest.cpp

Index: third_party/WebKit/Source/wtf/VectorTest.cpp
diff --git a/third_party/WebKit/Source/wtf/VectorTest.cpp b/third_party/WebKit/Source/wtf/VectorTest.cpp
index d06b47be7bf0215dc50edbf1bd1879bc0b504fef..447edd090448b5c7f5577b89cf19a7ba7a08c134 100644
--- a/third_party/WebKit/Source/wtf/VectorTest.cpp
+++ b/third_party/WebKit/Source/wtf/VectorTest.cpp
@@ -459,6 +459,31 @@ TEST(VectorTest, AppendFirst)
         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 {
+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