Convert Settings::rootLayerScrolls to RuntimeEnabledFeatures

third_party/WebKit/Source/platform/testing/RuntimeEnabledFeaturesTestHelpers.h

+// Copyright 2016 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 RuntimeEnabledFeaturesTestHelpers_h
+#define RuntimeEnabledFeaturesTestHelpers_h
+
+#include "platform/RuntimeEnabledFeatures.h"
+#include "wtf/Assertions.h"
+
+namespace blink {
+
+template <bool(&getter)(), void(&setter)(bool)>
+class ScopedRuntimeEnabledFeatureForTest {
+public:
+    ScopedRuntimeEnabledFeatureForTest(bool enabled)
+        : m_enabled(enabled)
+        , m_original(getter())
+    {
+        setter(enabled);
+    }
+
+    ~ScopedRuntimeEnabledFeatureForTest()
+    {
+        CHECK_EQ(m_enabled, getter());
+        setter(m_original);
+    }
+
+private:
+    bool m_enabled;
+    bool m_original;
+};
+
+typedef ScopedRuntimeEnabledFeatureForTest<RuntimeEnabledFeatures::compositorWorkerEnabled, RuntimeEnabledFeatures::setCompositorWorkerEnabled> ScopedCompositorWorkerForTest;
+typedef ScopedRuntimeEnabledFeatureForTest<RuntimeEnabledFeatures::rootLayerScrollingEnabled, RuntimeEnabledFeatures::setRootLayerScrollingEnabled> ScopedRootLayerScrollingForTest;
+typedef ScopedRuntimeEnabledFeatureForTest<RuntimeEnabledFeatures::slimmingPaintV2Enabled, RuntimeEnabledFeatures::setSlimmingPaintV2Enabled> ScopedSlimmingPaintV2ForTest;
+
+} // namespace blink
+
+#endif // RuntimeEnabledFeaturesTestHelpers_h