[SPv2] Defer decision of raster invalidation after paint for changes z-index, transform, etc.

third_party/WebKit/Source/core/layout/LayoutObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1403 matching lines @@
 }
 
 StyleDifference LayoutObject::adjustStyleDifference(StyleDifference diff) const
 {
     if (diff.transformChanged() && isSVG()) {
         // Skip a full layout for transforms at the html/svg boundary which do not affect sizes inside SVG.
         if (!isSVGRoot())
             diff.setNeedsFullLayout();
     }
 
-    // If transform changed, and the layer does not paint into its own separate backing, then we need to invalidate paints.
-    if (diff.transformChanged()) {
-        // Text nodes share style with their parents but transforms don't apply to them,
+    if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
+        // Text nodes share style with their parents but the checked styles don't apply to them,
         // hence the !isText() check.
-        if (!isText() && (!hasLayer() || !toLayoutBoxModelObject(this)->layer()->hasStyleDeterminedDirectCompositingReasons()))
-            diff.setNeedsPaintInvalidationSubtree();
-    }
+        if (!isText()
+            && (diff.transformChanged() || diff.opacityChanged() || diff.zIndexChanged() || diff.filterChanged() || diff.backdropFilterChanged())) {
+            // We don't need to invalidate paint of objects on SPv2 when only paint property or
+            // paint order change. Mark the painting layer needing repaint for changed paint
+            // property or paint order. Raster invalidation will be issued if needed during paint.
+            ObjectPaintInvalidator(*this).slowSetPaintingLayerNeedsRepaint();
+        }
+    } else {
+        // If transform changed, and the layer does not paint into its own separate backing, then we need to invalidate paints.
+        if (diff.transformChanged()) {
+            // Text nodes share style with their parents but transforms don't apply to them,
+            // hence the !isText() check.
+            if (!isText() && (!hasLayer() || !toLayoutBoxModelObject(this)->layer()->hasStyleDeterminedDirectCompositingReasons()))
+                diff.setNeedsPaintInvalidationSubtree();
+        }
 
-    // If opacity or zIndex changed, and the layer does not paint into its own separate backing, then we need to invalidate paints (also
-    // ignoring text nodes)
-    if (diff.opacityChanged() || diff.zIndexChanged()) {
-        if (!isText() && (!hasLayer() || !toLayoutBoxModelObject(this)->layer()->hasStyleDeterminedDirectCompositingReasons()))
-            diff.setNeedsPaintInvalidationSubtree();
-    }
+        // If opacity or zIndex changed, and the layer does not paint into its own separate backing, then we need to invalidate paints (also
+        // ignoring text nodes)
+        if (diff.opacityChanged() || diff.zIndexChanged()) {
+            if (!isText() && (!hasLayer() || !toLayoutBoxModelObject(this)->layer()->hasStyleDeterminedDirectCompositingReasons()))
+                diff.setNeedsPaintInvalidationSubtree();
+        }
 
-    // If filter changed, and the layer does not paint into its own separate backing or it paints with filters, then we need to invalidate paints.
-    if (diff.filterChanged() && hasLayer()) {
-        PaintLayer* layer = toLayoutBoxModelObject(this)->layer();
-        if (!layer->hasStyleDeterminedDirectCompositingReasons() || layer->paintsWithFilters())
-            diff.setNeedsPaintInvalidationSubtree();
-    }
+        // If filter changed, and the layer does not paint into its own separate backing or it paints with filters, then we need to invalidate paints.
+        if (diff.filterChanged() && hasLayer()) {
+            PaintLayer* layer = toLayoutBoxModelObject(this)->layer();
+            if (!layer->hasStyleDeterminedDirectCompositingReasons() || layer->paintsWithFilters())
+                diff.setNeedsPaintInvalidationSubtree();
+        }
 
-    // If backdrop filter changed, and the layer does not paint into its own separate backing or it paints with filters, then we need to invalidate paints.
-    if (diff.backdropFilterChanged() && hasLayer()) {
-        PaintLayer* layer = toLayoutBoxModelObject(this)->layer();
-        if (!layer->hasStyleDeterminedDirectCompositingReasons() || layer->paintsWithBackdropFilters())
-            diff.setNeedsPaintInvalidationSubtree();
+        // If backdrop filter changed, and the layer does not paint into its own separate backing or it paints with filters, then we need to invalidate paints.
+        if (diff.backdropFilterChanged() && hasLayer()) {
+            PaintLayer* layer = toLayoutBoxModelObject(this)->layer();
+            if (!layer->hasStyleDeterminedDirectCompositingReasons() || layer->paintsWithBackdropFilters())
+                diff.setNeedsPaintInvalidationSubtree();
+        }
     }
 
     // Optimization: for decoration/color property changes, invalidation is only needed if we have style or text affected by these properties.
     if (diff.textDecorationOrColorChanged() && !diff.needsPaintInvalidation()) {
         if (style()->hasBorder() || style()->hasOutline()
             || style()->hasBackgroundRelatedColorReferencingCurrentColor()
             // Skip any text nodes that do not contain text boxes. Whitespace cannot be
             // skipped or we will miss invalidating decorations (e.g., underlines).
             || (isText() && !isBR() && toLayoutText(this)->hasTextBoxes())
             // Caret is painted in text color.
@@ skipping 1772 matching lines @@
         const blink::LayoutObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
     } else {
         WTFLogAlways("%s", "Cannot showLayoutTree. Root is (nil)");
     }
 }
 
 #endif