Arrange compositor scrolling into scroll customization format

cc/layers/layer_impl.cc

 // Copyright 2012 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/layers/layer_impl.h"
 
 #include "base/json/json_reader.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "cc/animation/animation_registrar.h"
 #include "cc/animation/scrollbar_animation_controller.h"
 #include "cc/base/math_util.h"
 #include "cc/base/simple_enclosed_region.h"
 #include "cc/debug/debug_colors.h"
 #include "cc/debug/layer_tree_debug_state.h"
 #include "cc/debug/micro_benchmark_impl.h"
 #include "cc/debug/traced_value.h"
+#include "cc/input/scroll_state.h"
 #include "cc/layers/layer_utils.h"
 #include "cc/layers/painted_scrollbar_layer_impl.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/quads/debug_border_draw_quad.h"
 #include "cc/quads/render_pass.h"
 #include "cc/trees/layer_tree_host_common.h"
 #include "cc/trees/layer_tree_impl.h"
 #include "cc/trees/layer_tree_settings.h"
 #include "cc/trees/proxy.h"
 #include "ui/gfx/geometry/box_f.h"
@@ skipping 159 matching lines @@
   SetNeedsPushProperties();
 }
 
 void LayerImpl::SetScrollChildren(std::set<LayerImpl*>* children) {
   if (scroll_children_.get() == children)
     return;
   scroll_children_.reset(children);
   SetNeedsPushProperties();
 }
 
+void LayerImpl::DistributeScroll(ScrollState* scroll_state) {
+  DCHECK(scroll_state);
+  if (scroll_state->FullyConsumed())
+    return;
+
+  scroll_state->DistributeToScrollChainDescendant();
+
+  // If the scroll doesn't propagate, and we're currently scrolling
+  // a layer other than this one, prevent the scroll from
+  // propagating to this layer.
+  if (!scroll_state->should_propagate() &&
+      scroll_state->delta_consumed_for_scroll_sequence() &&
+      scroll_state->current_native_scrolling_layer() != this) {
+    return;
+  }
+
+  ApplyScroll(scroll_state);
+}
+
+void LayerImpl::ApplyScroll(ScrollState* scroll_state) {
+  DCHECK(scroll_state);
+  layer_tree_impl()->ApplyScroll(this, scroll_state);
+}
+
 void LayerImpl::SetNumDescendantsThatDrawContent(int num_descendants) {
   if (num_descendants_that_draw_content_ == num_descendants)
     return;
   num_descendants_that_draw_content_ = num_descendants;
   SetNeedsPushProperties();
 }
 
 void LayerImpl::SetClipParent(LayerImpl* ancestor) {
   if (clip_parent_ == ancestor)
     return;
@@ skipping 1599 matching lines @@
   }
 
   // TODO(enne): the transform needs to come from property trees instead of
   // draw properties.
   gfx::Vector2dF transform_scales = MathUtil::ComputeTransform2dScaleComponents(
       draw_properties().target_space_transform, default_scale);
   return std::max(transform_scales.x(), transform_scales.y());
 }
 
 }  // namespace cc