Store non-fast scrollable regions on ScrollNode

third_party/WebKit/Source/platform/graphics/compositing/PropertyTreeManager.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/PropertyTreeManager.h"
 
 #include "cc/layers/layer.h"
 #include "cc/trees/clip_node.h"
 #include "cc/trees/effect_node.h"
 #include "cc/trees/layer_tree_host.h"
@@ skipping 285 matching lines @@
   auto& compositorTransformNode = *transformTree().Node(transformNodeId);
 
   auto compositorElementId = scrollOffsetNode->compositorElementId();
   if (compositorElementId) {
     compositorScrollNode.element_id = compositorElementId;
     m_propertyTrees.element_id_to_scroll_node_index[compositorElementId] =
         scrollNodeId;
   }
 
   compositorScrollNode.transform_id = transformNodeId;
+  // TODO(pdr): Set the scroll node's non_fast_scrolling_region value.
 
   // Blink creates a 2d transform node just for scroll offset whereas cc's
   // transform node has a special scroll offset field. To handle this we adjust
   // cc's transform node to remove the 2d scroll translation and instead set the
   // scroll_offset field.
   auto scrollOffsetSize = scrollOffsetNode->matrix().to2DTranslation();
   auto scrollOffset =
       gfx::ScrollOffset(-scrollOffsetSize.width(), -scrollOffsetSize.height());
   DCHECK(compositorTransformNode.local.IsIdentityOr2DTranslation());
   compositorTransformNode.scroll_offset = scrollOffset;
@@ skipping 137 matching lines @@
   m_effectStack.push_back(BlinkEffectAndCcIdPair{nextEffect, effectNode.id});
 
   dummyLayer->set_property_tree_sequence_number(kPropertyTreeSequenceNumber);
   dummyLayer->SetTransformTreeIndex(kSecondaryRootNodeId);
   dummyLayer->SetClipTreeIndex(outputClipId);
   dummyLayer->SetEffectTreeIndex(effectNode.id);
   dummyLayer->SetScrollTreeIndex(kRealRootNodeId);
 }
 
 }  // namespace blink