Implement CSS: scroll-boundary-behavior

cc/layers/layer_impl.h

 // 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.
 
 #ifndef CC_LAYERS_LAYER_IMPL_H_
 #define CC_LAYERS_LAYER_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <map>
 #include <memory>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/values.h"
 #include "cc/base/region.h"
 #include "cc/base/synced_property.h"
 #include "cc/cc_export.h"
 #include "cc/debug/layer_tree_debug_state.h"
 #include "cc/input/input_handler.h"
+#include "cc/input/scroll_boundary_behavior.h"
 #include "cc/layers/draw_mode.h"
 #include "cc/layers/draw_properties.h"
 #include "cc/layers/layer_collections.h"
 #include "cc/layers/layer_impl_test_properties.h"
 #include "cc/layers/layer_position_constraint.h"
 #include "cc/layers/performance_properties.h"
 #include "cc/layers/render_surface_impl.h"
 #include "cc/layers/touch_action_region.h"
 #include "cc/quads/shared_quad_state.h"
 #include "cc/resources/resource_provider.h"
@@ skipping 248 matching lines @@
     return viewport_layer_type() != NOT_VIEWPORT_LAYER;
   }
 
   void SetCurrentScrollOffset(const gfx::ScrollOffset& scroll_offset);
   gfx::ScrollOffset CurrentScrollOffset() const;
 
   gfx::ScrollOffset MaxScrollOffset() const;
   gfx::ScrollOffset ClampScrollOffsetToLimits(gfx::ScrollOffset offset) const;
   gfx::Vector2dF ClampScrollToMaxScrollOffset();
 
+  void SetScrollBoundaryBehavior(const ScrollBoundaryBehavior&);
+  ScrollBoundaryBehavior scroll_boundary_behavior() {
+    return scroll_boundary_behavior_;

[ajuma, 2017/06/30 20:46:49]

Does LayerImpl need to have a copy of this value, or is it enough for ScrollNode
to have it? If it's needed just for tests, it can be moved to
LayerImplTestProperties.

[sunyunjia, 2017/07/14 02:59:00]

Done.

+  }
+
   // Returns the delta of the scroll that was outside of the bounds of the
   // initial scroll
   gfx::Vector2dF ScrollBy(const gfx::Vector2dF& scroll);
 
   // Marks this layer as being scrollable and needing an associated scroll node.
   // The scroll node's bounds and scroll_clip_layer_bounds will be kept in sync
   // with this layer.
   void SetScrollable(const gfx::Size& bounds);
   gfx::Size scroll_container_bounds() const { return scroll_container_bounds_; }
   bool scrollable() const { return scrollable_; }
@@ skipping 254 matching lines @@
   bool needs_show_scrollbars_ : 1;
 
   // This is set for layers that have a property because of which they are not
   // drawn (singular transforms), but they can become visible soon (the property
   // is being animated). For this reason, while these layers are not drawn, they
   // are still rasterized.
   bool raster_even_if_not_drawn_ : 1;
 
   bool has_transform_node_ : 1;
 
+  ScrollBoundaryBehavior scroll_boundary_behavior_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_IMPL_H_