Implement CSS: scroll-boundary-behavior

cc/layers/layer.h

Index: cc/layers/layer.h
diff --git a/cc/layers/layer.h b/cc/layers/layer.h
index b63ad10e0a07287aaa7e16c241d71e6a7ededa96..e3ba7526f7cffb079c0cc8b3ea9e4eedabf6c246 100644
--- a/cc/layers/layer.h
+++ b/cc/layers/layer.h
@@ -22,6 +22,7 @@
 #include "cc/benchmarks/micro_benchmark.h"
 #include "cc/cc_export.h"
 #include "cc/input/input_handler.h"
+#include "cc/input/scroll_boundary_behavior.h"
 #include "cc/layers/layer_collections.h"
 #include "cc/layers/layer_position_constraint.h"
 #include "cc/layers/touch_action_region.h"
@@ -114,6 +115,11 @@ class CC_EXPORT Layer : public base::RefCounted<Layer> {
   void SetBounds(const gfx::Size& bounds);
   gfx::Size bounds() const { return inputs_.bounds; }
 
+  void SetScrollBoundaryBehavior(const ScrollBoundaryBehavior& behavior);
+  ScrollBoundaryBehavior scroll_boundary_behavior() const {
+    return inputs_.scroll_boundary_behavior;
+  }
+
   void SetMasksToBounds(bool masks_to_bounds);
   bool masks_to_bounds() const { return inputs_.masks_to_bounds; }
 
@@ -606,6 +612,8 @@ class CC_EXPORT Layer : public base::RefCounted<Layer> {
     LayerClient* client;
     base::Callback<void(const gfx::ScrollOffset&)> did_scroll_callback;
     std::vector<std::unique_ptr<CopyOutputRequest>> copy_requests;
+
+    ScrollBoundaryBehavior scroll_boundary_behavior;
   };
 
   Layer* parent_;