Use scoped REF test helpers for SPv2 and RootLayerScrolls.

third_party/WebKit/Source/platform/graphics/paint/PaintChunkerTest.cpp

 // Copyright 2015 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 "platform/graphics/paint/PaintChunker.h"
 
-#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/testing/PaintPropertyTestHelpers.h"
+#include "platform/testing/RuntimeEnabledFeaturesTestHelpers.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using ::blink::testing::createOpacityOnlyEffect;
 using ::blink::testing::defaultPaintChunkProperties;
 using ::testing::ElementsAre;
 
 namespace blink {
 namespace {
 
-class PaintChunkerTest : public ::testing::Test {
- protected:
-  void SetUp() override {
-    RuntimeEnabledFeatures::setSlimmingPaintV2Enabled(true);
-  }
-
-  void TearDown() override { m_featuresBackup.restore(); }
+class PaintChunkerTest : public ::testing::Test,
+                         private ScopedSlimmingPaintV2ForTest {
+ public:
+  PaintChunkerTest() : ScopedSlimmingPaintV2ForTest(true) {}
 
  protected:
   class TestDisplayItemClient : public DisplayItemClient {
     String debugName() const final { return "Test"; }
     LayoutRect visualRect() const final { return LayoutRect(); }
   };
   TestDisplayItemClient m_client;
-
- private:
-  RuntimeEnabledFeatures::Backup m_featuresBackup;
 };
 
 class TestDisplayItem : public DisplayItem {
  public:
   TestDisplayItem(const DisplayItemClient& client, DisplayItem::Type type)
       : DisplayItem(client, type, sizeof(*this)) {}
 
   void replay(GraphicsContext&) const final { NOTREACHED(); }
   void appendToWebDisplayItemList(const IntRect&,
                                   WebDisplayItemList*) const final {
@@ skipping 333 matching lines @@
       chunks,
       ElementsAre(PaintChunk(0, 2, nullptr, defaultPaintChunkProperties()),
                   PaintChunk(2, 4, nullptr, simpleTransform),
                   PaintChunk(4, 5, nullptr, simpleTransform),
                   PaintChunk(5, 6, nullptr, simpleTransform),
                   PaintChunk(6, 7, nullptr, defaultPaintChunkProperties())));
 }
 
 }  // namespace
 }  // namespace blink