Disable some PaintPropertyTreeBuilder features for SPv1 SlimmingPaintInvalidation

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

Index: third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
index 6baebf02bfb5a7794626ffa4a5af5af5d5137593..0f2a240523c2117b69d7d210c97bbad3833907ec 100644
--- a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
@@ -357,15 +357,22 @@ void PaintPropertyTreeBuilder::updateTransform(
   if (object.needsPaintPropertyUpdate() || context.forceSubtreeUpdate) {
     const ComputedStyle& style = object.styleRef();
 
-    CompositingReasons compositingReasons =
-        compositingReasonsForTransform(object);
-
-    // A transform node is allocated for transforms, preserves-3d and any
-    // direct compositing reason. The latter is required because this is the
-    // only way to represent compositing both an element and its stacking
-    // descendants.
-    if (object.isBox() && (style.hasTransform() || style.preserves3D() ||
-                           compositingReasons != CompositingReasonNone)) {
+    bool needsTransformNode = false;
+    CompositingReasons compositingReasons = CompositingReasonNone;
+    if (object.isBox()) {
+      // A transform node is allocated for transforms, preserves-3d (SPv2) and
+      // any direct compositing reason (SPv2). The latter is required because
+      // this is the only way to represent compositing both an element and its
+      // stacking descendants.
+      needsTransformNode |= style.hasTransform();
+      if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
+        needsTransformNode |= style.preserves3D();

[chrishtr, 2016/12/28 18:15:18]

Are you sure preserve-3D is not required for SlimmingPaintInvalidation?

[Xianzhu, 2016/12/28 18:25:29]

Yes. GeometryMapper doesn't use FlattenInheritedTransform.

+        compositingReasons = compositingReasonsForTransform(object);
+        needsTransformNode |= (compositingReasons != CompositingReasonNone);
+      }
+    }
+
+    if (needsTransformNode) {
       auto& box = toLayoutBox(object);
       TransformationMatrix matrix;
       style.applyTransform(
@@ -378,7 +385,8 @@ void PaintPropertyTreeBuilder::updateTransform(
       // If a node with transform-style: preserve-3d does not exist in an
       // existing rendering context, it establishes a new one.
       unsigned renderingContextID = context.current.renderingContextID;
-      if (style.preserves3D() && !renderingContextID)
+      if (RuntimeEnabledFeatures::slimmingPaintV2Enabled() &&
+          style.preserves3D() && !renderingContextID)
         renderingContextID = PtrHash<const LayoutObject>::hash(&object);
 
       auto& properties = object.getMutableForPainting().ensurePaintProperties();
@@ -395,7 +403,8 @@ void PaintPropertyTreeBuilder::updateTransform(
   const auto* properties = object.paintProperties();
   if (properties && properties->transform()) {
     context.current.transform = properties->transform();
-    if (object.styleRef().preserves3D()) {
+    if (RuntimeEnabledFeatures::slimmingPaintV2Enabled() &&
+        object.styleRef().preserves3D()) {
       context.current.renderingContextID =
           properties->transform()->renderingContextID();
       context.current.shouldFlattenInheritedTransform = false;
@@ -409,6 +418,9 @@ void PaintPropertyTreeBuilder::updateTransform(
 void PaintPropertyTreeBuilder::updateEffect(
     const LayoutObject& object,
     PaintPropertyTreeBuilderContext& context) {
+  if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+    return;
+
   const ComputedStyle& style = object.styleRef();
 
   const bool isCSSIsolatedGroup =