cc : Snap texture layers to pixel boundary

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 <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 304 matching lines @@
 bool LayerImpl::user_scrollable(ScrollbarOrientation orientation) const {
   return (orientation == HORIZONTAL) ? user_scrollable_horizontal_
                                      : user_scrollable_vertical_;
 }
 
 std::unique_ptr<LayerImpl> LayerImpl::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
   return LayerImpl::Create(tree_impl, layer_id_);
 }
 
+bool LayerImpl::IsSnapped() {
+  return scrollable();
+}
+
 void LayerImpl::PushPropertiesTo(LayerImpl* layer) {
   DCHECK(layer->IsActive());
 
   layer->offset_to_transform_parent_ = offset_to_transform_parent_;
   layer->main_thread_scrolling_reasons_ = main_thread_scrolling_reasons_;
   layer->user_scrollable_horizontal_ = user_scrollable_horizontal_;
   layer->user_scrollable_vertical_ = user_scrollable_vertical_;
   layer->should_flatten_transform_from_property_tree_ =
       should_flatten_transform_from_property_tree_;
   layer->masks_to_bounds_ = masks_to_bounds_;
@@ skipping 758 matching lines @@
            .layer_transforms_should_scale_layer_contents) {
     return default_scale;
   }
 
   gfx::Vector2dF transform_scales = MathUtil::ComputeTransform2dScaleComponents(
       ScreenSpaceTransform(), default_scale);
   return std::max(transform_scales.x(), transform_scales.y());
 }
 
 }  // namespace cc