Add background attachment fixed main thread scrolling reason [spv2]

third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositorTest.cpp

Index: third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositorTest.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositorTest.cpp b/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositorTest.cpp
index 079db6539672fe75b9fc1f035690307dec90b527..30a37499fad58b6eae9144b32bcf158a7434fe1a 100644
--- a/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositorTest.cpp
+++ b/third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositorTest.cpp
@@ -569,6 +569,8 @@ TEST_F(PaintArtifactCompositorTestWithPropertyTrees, OneScrollNode)
     EXPECT_TRUE(transformNode.local.IsIdentity());
 
     EXPECT_EQ(gfx::ScrollOffset(-7, -9), scrollTree.current_scroll_offset(contentLayerAt(0)->id()));
+
+    EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain, scrollNode.main_thread_scrolling_reasons);
 }
 
 TEST_F(PaintArtifactCompositorTestWithPropertyTrees, NestedScrollNodes)
@@ -583,6 +585,7 @@ TEST_F(PaintArtifactCompositorTestWithPropertyTrees, NestedScrollNodes)
         scrollTranslationA, TransformationMatrix().translate(37, 41), FloatPoint3D());
     RefPtr<ScrollPaintPropertyNode> scrollB = ScrollPaintPropertyNode::create(
         scrollA, scrollTranslationB, IntSize(19, 23), IntSize(29, 31), true, false);
+    scrollB->setBackgroundAttachmentFixedMainThreadScrollingReason();
 
     TestPaintArtifact artifact;
     artifact.chunk(scrollTranslationA, nullptr, effect, scrollA)
@@ -615,6 +618,10 @@ TEST_F(PaintArtifactCompositorTestWithPropertyTrees, NestedScrollNodes)
 
     EXPECT_EQ(gfx::ScrollOffset(-11, -13), scrollTree.current_scroll_offset(contentLayerAt(0)->id()));
     EXPECT_EQ(gfx::ScrollOffset(-37, -41), scrollTree.current_scroll_offset(contentLayerAt(1)->id()));
+
+    // The main thread scrolling bits from scrollNodeB should have been propagated to scrollNodeA.
+    EXPECT_TRUE(scrollNodeA.main_thread_scrolling_reasons & MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects);
+    EXPECT_TRUE(scrollNodeB.main_thread_scrolling_reasons & MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects);
 }
 
 } // namespace