Add background attachment fixed main thread scrolling reason [spv2]

third_party/WebKit/Source/platform/graphics/compositing/PaintArtifactCompositor.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/compositing/PaintArtifactCompositor.h"
 
 #include "cc/layers/content_layer_client.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/picture_layer.h"
 #include "cc/playback/display_item_list.h"
@@ skipping 354 matching lines @@
         return it->value;
 
     int parentId = compositorIdForScrollNode(scrollNode->parent());
     int id = scrollTree().Insert(cc::ScrollNode(), parentId);
 
     cc::ScrollNode& compositorNode = *scrollTree().Node(id);
     compositorNode.owner_id = parentId;
 
     compositorNode.scrollable = true;
 
-    // TODO(pdr): Set main thread scrolling reasons.
     compositorNode.scroll_clip_layer_bounds.SetSize(scrollNode->clip().width(), scrollNode->clip().height());
     compositorNode.bounds.SetSize(scrollNode->bounds().width(), scrollNode->bounds().height());
     compositorNode.user_scrollable_horizontal = scrollNode->userScrollableHorizontal();
     compositorNode.user_scrollable_vertical = scrollNode->userScrollableVertical();
     compositorNode.transform_id = compositorIdForTransformNode(scrollNode->scrollOffsetTranslation());
+    compositorNode.main_thread_scrolling_reasons = scrollNode->mainThreadScrollingReasons();
 
     auto result = m_scrollNodeMap.set(scrollNode, id);
     DCHECK(result.isNewEntry);
     scrollTree().set_needs_update(true);
 
     return id;
 }
 
 void PropertyTreeManager::updateScrollOffset(int layerId, int scrollId)
 {
@@ skipping 156 matching lines @@
         if (m_extraDataForTestingEnabled)
             m_extraDataForTesting->contentLayers.append(layer);
     }
 
     // Mark the property trees as having been rebuilt.
     layerTree->property_trees()->sequence_number = kPropertyTreeSequenceNumber;
     layerTree->property_trees()->needs_rebuild = false;
 }
 
 } // namespace blink