Raster PictureLayerTiling with fractional translation

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 487 matching lines @@
       }
     } else {
       if (hasScrollingLayer())
         m_scrollingContentsLayer->setContentsOpaque(false);
       m_graphicsLayer->setContentsOpaque(
           m_owningLayer.backgroundIsKnownToBeOpaqueInRect(compositedBounds()));
     }
   }
 }
 
+void CompositedLayerMapping::updateRasterizationPolicy() {
+  bool allowTransformedRasterization =
+      !requiresCompositing(m_owningLayer.getCompositingReasons() &
+                           ~CompositingReasonSquashingDisallowed);
+  m_graphicsLayer->contentLayer()->setAllowTransformedRasterization(
+      allowTransformedRasterization);
+  if (m_squashingLayer)
+    m_squashingLayer->contentLayer()->setAllowTransformedRasterization(true);
+}
+
 void CompositedLayerMapping::updateCompositedBounds() {
   DCHECK_EQ(m_owningLayer.compositor()->lifecycle().state(),
             DocumentLifecycle::InCompositingUpdate);
   // FIXME: if this is really needed for performance, it would be better to
   // store it on Layer.
   m_compositedBounds = m_owningLayer.boundingBoxForCompositing();
   m_contentOffsetInCompositingLayerDirty = true;
 }
 
 void CompositedLayerMapping::updateAfterPartResize() {
@@ skipping 594 matching lines @@
     m_owningLayer.getScrollableArea()->positionOverflowControls();
 
   updateLayerBlendMode(layoutObject().styleRef());
   updateIsRootForIsolatedGroup();
   updateContentsRect();
   updateBackgroundColor();
   updateDrawsContent();
   updateElementIdAndCompositorMutableProperties();
   updateBackgroundPaintsOntoScrollingContentsLayer();
   updateContentsOpaque();
+  updateRasterizationPolicy();
   updateAfterPartResize();
   updateRenderingContext();
   updateShouldFlattenTransform();
   updateChildrenTransform();
   updateScrollParent(scrollParent());
   registerScrollingLayers();
 
   updateCompositingReasons();
 }
 
@@ skipping 2407 matching lines @@
   } else if (graphicsLayer == m_decorationOutlineLayer.get()) {
     name = "Decoration Layer";
   } else {
     NOTREACHED();
   }
 
   return name;
 }
 
 }  // namespace blink