Web Animations: Add InterpolableValue hierarchy.

Source/core/animation/InterpolableValue.cpp

Index: Source/core/animation/InterpolableValue.cpp
diff --git a/Source/core/animation/InterpolableValue.cpp b/Source/core/animation/InterpolableValue.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..6e1f0b29e010d179ef72f1e7720112655168433c
--- /dev/null
+++ b/Source/core/animation/InterpolableValue.cpp
@@ -0,0 +1,49 @@
+// 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.
+
+#include "config.h"
+#include "core/animation/InterpolableValue.h"
+
+namespace WebCore {
+
+PassOwnPtr<InterpolableValue> InterpolableNumber::interpolate(const InterpolableValue &other, double progress) const
+{
+    const InterpolableNumber* otherNumber = toInterpolableNumber(&other);
+    if (!progress)
+        return create(m_value);
+    if (progress == 1)
+        return create(otherNumber->m_value);
+    return create(m_value * (1 - progress) + otherNumber->m_value * progress);
+}
+
+PassOwnPtr<InterpolableValue> InterpolableBool::interpolate(const InterpolableValue &other, double progress) const
+{
+    if (progress < 0.5) {
+        return clone();
+    }
+    return other.clone();
+}
+
+PassOwnPtr<InterpolableValue> InterpolableList::interpolate(const InterpolableValue &other, double progress) const
+{
+    const InterpolableList* otherList = toInterpolableList(&other);
+    ASSERT(otherList->m_size == m_size);
+
+    if (!progress) {
+        return create(*this);
+    }
+    if (progress == 1) {
+        return InterpolableList::create(*otherList);
+    }
+
+    OwnPtr<InterpolableList> result = create(m_size);
+    for (size_t i = 0; i < m_size; i++) {
+        ASSERT(m_values.get()[i]);
+        ASSERT(otherList->m_values.get()[i]);
+        result->set(i, m_values.get()[i]->interpolate(*(otherList->m_values.get()[i]), progress));
+    }
+    return result.release();
+}
+
+}