Implement CSS: scroll-boundary-behavior

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 63 matching lines @@
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/paint/ClipDisplayItem.h"
 #include "platform/graphics/paint/CullRect.h"
 #include "platform/graphics/paint/DrawingRecorder.h"
 #include "platform/graphics/paint/PaintController.h"
 #include "platform/graphics/paint/PaintRecordBuilder.h"
 #include "platform/graphics/paint/TransformDisplayItem.h"
 #include "platform/wtf/CurrentTime.h"
 #include "platform/wtf/text/StringBuilder.h"
 #include "public/platform/WebLayerStickyPositionConstraint.h"
+#include "public/platform/WebScrollBoundaryBehavior.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 static IntRect ClipBox(LayoutBox& layout_object);
 
 static IntRect ContentsRect(const LayoutObject& layout_object) {
   if (!layout_object.IsBox())
     return IntRect();
@@ skipping 1037 matching lines @@
   UpdateDrawsContent();
   UpdateElementId();
   UpdateBackgroundPaintsOntoScrollingContentsLayer();
   UpdateContentsOpaque();
   UpdateRasterizationPolicy();
   UpdateAfterPartResize();
   UpdateRenderingContext();
   UpdateShouldFlattenTransform();
   UpdateChildrenTransform();
   UpdateScrollParent(ScrollParent());
+  UpdateScrollBoundaryBehavior();
   RegisterScrollingLayers();
 
   UpdateCompositingReasons();
 }
 
+void CompositedLayerMapping::UpdateScrollBoundaryBehavior() {
+  EScrollBoundaryBehavior behavior_x =
+      GetLayoutObject().StyleRef().ScrollBoundaryBehaviorX();
+  EScrollBoundaryBehavior behavior_y =
+      GetLayoutObject().StyleRef().ScrollBoundaryBehaviorY();
+  if (scrolling_contents_layer_) {
+    scrolling_contents_layer_->SetScrollBoundaryBehavior(
+        WebScrollBoundaryBehavior(
+            static_cast<WebScrollBoundaryBehavior::ScrollBoundaryBehaviorType>(
+                behavior_x),
+            static_cast<WebScrollBoundaryBehavior::ScrollBoundaryBehaviorType>(
+                behavior_y)));
+  }
+}
+
 void CompositedLayerMapping::UpdateMainGraphicsLayerGeometry(
     const IntRect& relative_compositing_bounds,
     const IntRect& local_compositing_bounds,
     const IntPoint& graphics_layer_parent_location) {
   // Find and remove the offset applied for sticky position if the compositor
   // will shift the layer for sticky position to avoid offsetting the layer
   // twice.
   FloatSize offset_for_sticky_position;
   if (UsesCompositedStickyPosition()) {
     const StickyConstraintsMap& constraints_map =
@@ skipping 2442 matching lines @@
   } else if (graphics_layer == decoration_outline_layer_.get()) {
     name = "Decoration Layer";
   } else {
     NOTREACHED();
   }
 
   return name;
 }
 
 }  // namespace blink