Do not use new struct type where unnecessary.

src/objects/literal-objects.h

Index: src/objects/literal-objects.h
diff --git a/src/objects/literal-objects.h b/src/objects/literal-objects.h
index fdd321e74e6cf8f9f8a441f6cd86eedcb75d46cb..40bf70d602c50fb963d2945a8c3d4359dea90778 100644
--- a/src/objects/literal-objects.h
+++ b/src/objects/literal-objects.h
@@ -40,20 +40,15 @@ class BoilerplateDescription : public FixedArray {
 // Pair of {ElementsKind} and an array of constant values for {ArrayLiteral}
 // expressions. Used to communicate with the runtime for literal boilerplate
 // creation within the {Runtime_CreateArrayLiteral} method.
-class ConstantElementsPair : public Struct {
+class ConstantElementsPair : public Tuple2 {
  public:
   DECL_INT_ACCESSORS(elements_kind)
   DECL_ACCESSORS(constant_values, FixedArrayBase)
 
   DECLARE_CAST(ConstantElementsPair)
 
-  // Dispatched behavior.
-  DECLARE_PRINTER(ConstantElementsPair)
-  DECLARE_VERIFIER(ConstantElementsPair)
-
-  static const int kElementsKindOffset = HeapObject::kHeaderSize;
-  static const int kConstantValuesOffset = kElementsKindOffset + kPointerSize;
-  static const int kSize = kConstantValuesOffset + kPointerSize;
+  static const int kElementsKindOffset = kValue1Offset;
+  static const int kConstantValuesOffset = kValue2Offset;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ConstantElementsPair);