[not for review - epic CL] Adding Elastic+Momentum+Layered scrolling to views::ScrollView

cc/trees/layer_tree_host_common.cc

 // Copyright 2011 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 "cc/trees/layer_tree_host_common.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 154 matching lines @@
                                         device_viewport_size,
                                         gfx::Transform(),
                                         device_scale_factor,
                                         render_surface_layer_list) {}
 
 LayerTreeHostCommon::ScrollUpdateInfo::ScrollUpdateInfo()
     : layer_id(Layer::INVALID_ID) {}
 
 bool LayerTreeHostCommon::ScrollUpdateInfo::operator==(
     const LayerTreeHostCommon::ScrollUpdateInfo& other) const {
-  return layer_id == other.layer_id && scroll_delta == other.scroll_delta;
+  return layer_id == other.layer_id && scroll_delta == other.scroll_delta &&
+         overscroll == other.overscroll;
 }
 
 void LayerTreeHostCommon::ScrollUpdateInfo::ToProtobuf(
     proto::ScrollUpdateInfo* proto) const {
   proto->set_layer_id(layer_id);
   Vector2dToProto(scroll_delta, proto->mutable_scroll_delta());
+  ScrollOffsetToProto(overscroll, proto->mutable_overscroll());
 }
 
 void LayerTreeHostCommon::ScrollUpdateInfo::FromProtobuf(
     const proto::ScrollUpdateInfo& proto) {
   layer_id = proto.layer_id();
   scroll_delta = ProtoToVector2d(proto.scroll_delta());
+  overscroll = ProtoToScrollOffset(proto.overscroll());
 }
 
 ScrollAndScaleSet::ScrollAndScaleSet()
     : page_scale_delta(1.f), top_controls_delta(0.f) {
 }
 
 ScrollAndScaleSet::~ScrollAndScaleSet() {}
 
 bool ScrollAndScaleSet::EqualsForTesting(const ScrollAndScaleSet& other) const {
   return scrolls == other.scrolls &&
@@ skipping 515 matching lines @@
 
 PropertyTrees* GetPropertyTrees(Layer* layer) {
   return layer->GetLayerTree()->property_trees();
 }
 
 PropertyTrees* GetPropertyTrees(LayerImpl* layer) {
   return layer->layer_tree_impl()->property_trees();
 }
 
 }  // namespace cc