Reuse cc::PictureLayers when possible for SPv2.

third_party/WebKit/Source/core/paint/PaintInvalidator.cpp

Index: third_party/WebKit/Source/core/paint/PaintInvalidator.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintInvalidator.cpp b/third_party/WebKit/Source/core/paint/PaintInvalidator.cpp
index 98c7ff587eb23bc5538ef96a84bd6831d0211b32..3915700f50a63f9a22786b3505e28378595bc9f5 100644
--- a/third_party/WebKit/Source/core/paint/PaintInvalidator.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintInvalidator.cpp
@@ -53,13 +53,18 @@ static LayoutRect mapLocalRectToPaintInvalidationBacking(GeometryMapper& geometr
     } else if (object == context.paintInvalidationContainer) {
         result = LayoutRect(rect);
     } else {
+        rect.moveBy(FloatPoint(context.treeBuilderContext.current.paintOffset));
+
+        // In SPv2, visual rects are in the space of their local transform node.
+        if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())

[chrishtr, 2016/09/20 22:40:58]

In a followup I propose to simplify the code in this class for SPv2. SPv2
doesn't need the notion of a
paint invalidation container at all. WDYT?

[Xianzhu, 2016/09/20 23:13:41]

Agreed.

+            return LayoutRect(rect);
+
+        bool success = false;

[Xianzhu, 2016/09/20 23:13:41]

Nit: don't move this line.

[chrishtr, 2016/09/20 23:43:59]

Done.

[pdr., 2016/09/21 02:46:13]

Nit: move this back down

         GeometryPropertyTreeState currentTreeState(context.treeBuilderContext.current.transform, context.treeBuilderContext.current.clip, context.treeBuilderContext.currentEffect);
         GeometryPropertyTreeState containerTreeState;
         const ObjectPaintProperties* containerPaintProperties = context.paintInvalidationContainer->objectPaintProperties();
         containerPaintProperties->getContentsProperties(containerTreeState);
 
-        rect.moveBy(FloatPoint(context.treeBuilderContext.current.paintOffset));
-        bool success = false;
         result = LayoutRect(geometryMapper.mapToVisualRectInDestinationSpace(rect, currentTreeState, containerTreeState, success));
         DCHECK(success);
         result.moveBy(-containerPaintProperties->localBorderBoxProperties()->paintOffset);