Initial scroll-blocks-on compositor integration

Source/core/rendering/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 218 matching lines @@
 #endif
 
     updateOpacity(renderer()->style());
     updateTransform(renderer()->style());
     updateFilters(renderer()->style());
 
     if (RuntimeEnabledFeatures::cssCompositingEnabled()) {
         updateLayerBlendMode(renderer()->style());
         updateIsRootForIsolatedGroup();
     }
+
+    updateScrollBlocksOn(renderer()->style());
 }
 
 void CompositedLayerMapping::destroyGraphicsLayers()
 {
     if (m_graphicsLayer)
         m_graphicsLayer->removeFromParent();
 
     m_ancestorClippingLayer = nullptr;
     m_graphicsLayer = nullptr;
     m_foregroundLayer = nullptr;
@@ skipping 39 matching lines @@
 void CompositedLayerMapping::updateIsRootForIsolatedGroup()
 {
     bool isolate = m_owningLayer.shouldIsolateCompositedDescendants();
 
     // non stacking context layers should never isolate
     ASSERT(m_owningLayer.stackingNode()->isStackingContext() || !isolate);
 
     m_graphicsLayer->setIsRootForIsolatedGroup(isolate);
 }
 
+void CompositedLayerMapping::updateScrollBlocksOn(const RenderStyle* style)
+{
+    // Note that blink determines the default scroll blocking policy, even
+    // when the scroll-blocks-on CSS feature isn't enabled.
+    WebScrollBlocksOn blockingMode = WebScrollBlocksOnStartTouch | WebScrollBlocksOnWheelEvent;
+
+    if (RuntimeEnabledFeatures::cssScrollBlocksOnEnabled())
+        blockingMode = style->scrollBlocksOn();
+
+    m_graphicsLayer->setScrollBlocksOn(blockingMode);
+}
+
 void CompositedLayerMapping::updateContentsOpaque()
 {
     ASSERT(m_isMainFrameRenderViewLayer || !m_backgroundLayer);
     if (isAcceleratedCanvas(renderer())) {
         // Determine whether the rendering context's external texture layer is opaque.
         CanvasRenderingContext* context = toHTMLCanvasElement(renderer()->node())->renderingContext();
         if (!context->hasAlpha())
             m_graphicsLayer->setContentsOpaque(true);
         else if (WebLayer* layer = context->platformLayer())
             m_graphicsLayer->setContentsOpaque(!Color(layer->backgroundColor()).hasAlpha());
@@ skipping 400 matching lines @@
     updateBackgroundColor();
     updateDrawsContent();
     updateContentsOpaque();
     updateAfterPartResize();
     updateRenderingContext();
     updateShouldFlattenTransform();
     updateChildrenTransform();
     updateScrollParent(compositor()->preferCompositingToLCDTextEnabled() ? m_owningLayer.scrollParent() : 0);
     registerScrollingLayers();
 
+    updateScrollBlocksOn(renderer()->style());
+
     updateCompositingReasons();
 }
 
 void CompositedLayerMapping::updateMainGraphicsLayerGeometry(const IntRect& relativeCompositingBounds, const IntRect& localCompositingBounds, const IntPoint& graphicsLayerParentLocation)
 {
     m_graphicsLayer->setPosition(FloatPoint(relativeCompositingBounds.location() - graphicsLayerParentLocation));
     m_graphicsLayer->setOffsetFromRenderer(toIntSize(localCompositingBounds.location()));
 
     FloatSize oldSize = m_graphicsLayer->size();
     const IntSize& contentsSize = relativeCompositingBounds.size();
@@ skipping 1590 matching lines @@
     } else if (graphicsLayer == m_scrollingBlockSelectionLayer.get()) {
         name = "Scrolling Block Selection Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink