Add background attachment fixed main thread scrolling reason [spv2]

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

 // 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.
 
 #include "platform/graphics/compositing/PaintArtifactCompositor.h"
 
 #include "base/test/test_simple_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "cc/layers/layer.h"
 #include "cc/test/fake_compositor_frame_sink.h"
@@ skipping 551 matching lines @@
     EXPECT_EQ(gfx::Size(27, 31), scrollNode.bounds);
     EXPECT_TRUE(scrollNode.user_scrollable_horizontal);
     EXPECT_FALSE(scrollNode.user_scrollable_vertical);
     EXPECT_EQ(1, scrollNode.parent_id);
 
     const cc::TransformTree& transformTree = propertyTrees().transform_tree;
     const cc::TransformNode& transformNode = *transformTree.Node(scrollNode.transform_id);
     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)
 {
     RefPtr<EffectPaintPropertyNode> effect = EffectPaintPropertyNode::create(dummyRootEffect(), 0.5);
 
     RefPtr<TransformPaintPropertyNode> scrollTranslationA = TransformPaintPropertyNode::create(
         nullptr, TransformationMatrix().translate(11, 13), FloatPoint3D());
     RefPtr<ScrollPaintPropertyNode> scrollA = ScrollPaintPropertyNode::create(
         nullptr, scrollTranslationA, IntSize(2, 3), IntSize(5, 7), false, true);
     RefPtr<TransformPaintPropertyNode> scrollTranslationB = TransformPaintPropertyNode::create(
         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)
         .rectDrawing(FloatRect(7, 11, 13, 17), Color::white);
     artifact.chunk(scrollTranslationB, nullptr, effect, scrollB)
         .rectDrawing(FloatRect(1, 2, 3, 5), Color::white);
     update(artifact.build());
 
     const cc::ScrollTree& scrollTree = propertyTrees().scroll_tree;
     // Node #0 reserved for null; #1 for root render surface.
@@ skipping 12 matching lines @@
     EXPECT_EQ(scrollNodeA.id, scrollNodeB.parent_id);
 
     const cc::TransformTree& transformTree = propertyTrees().transform_tree;
     const cc::TransformNode& transformNodeA = *transformTree.Node(scrollNodeA.transform_id);
     EXPECT_TRUE(transformNodeA.local.IsIdentity());
     const cc::TransformNode& transformNodeB = *transformTree.Node(scrollNodeB.transform_id);
     EXPECT_TRUE(transformNodeB.local.IsIdentity());
 
     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
 } // namespace blink