New paint invalidation using paint property tree walk

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

Index: third_party/WebKit/Source/core/layout/LayoutObject.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.cpp b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
index ef6a026f77b402aab4fa4d816f4e805d3ca4472d..4a650a7f1f2886405e5c2f67614c7783e18a327f 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
@@ -256,10 +256,6 @@ LayoutObject::LayoutObject(Node* node)
 #endif
     , m_bitfields(node)
 {
-    // TODO(wangxianzhu): Move this into initialization list when we enable the feature by default.
-    if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled())
-        m_previousPositionFromPaintInvalidationBacking = uninitializedPaintOffset();
-
 #ifndef NDEBUG
     layoutObjectCounter().increment();
 #endif
@@ -1217,13 +1213,12 @@ static void invalidatePaintRectangleOnWindow(const LayoutBoxModelObject& paintIn
 
 void LayoutObject::invalidatePaintUsingContainer(const LayoutBoxModelObject& paintInvalidationContainer, const LayoutRect& dirtyRect, PaintInvalidationReason invalidationReason) const
 {
-    // TODO(wangxianzhu): Enable the following assert after paint invalidation for spv2 is ready.
-    // ASSERT(!RuntimeEnabledFeatures::slimmingPaintV2Enabled());
-
     if (paintInvalidationContainer.frameView()->shouldThrottleRendering())
         return;
 
-    ASSERT(gDisablePaintInvalidationStateAsserts || document().lifecycle().state() == DocumentLifecycle::InPaintInvalidation);
+    ASSERT(gDisablePaintInvalidationStateAsserts
+        || document().lifecycle().state() == DocumentLifecycle::InPaintInvalidation
+        || (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled() && document().lifecycle().state() == DocumentLifecycle::InPrePaintTreeWalk));
 
     if (dirtyRect.isEmpty())
         return;
@@ -1332,6 +1327,7 @@ void LayoutObject::invalidatePaintRectangleNotInvalidatingDisplayItemClients(con
 
 void LayoutObject::invalidateTreeIfNeeded(PaintInvalidationState& paintInvalidationState)
 {
+    ASSERT(!RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled());
     ASSERT(!needsLayout());
 
     // If we didn't need paint invalidation then our children don't need as well.
@@ -1350,6 +1346,8 @@ void LayoutObject::invalidateTreeIfNeeded(PaintInvalidationState& paintInvalidat
 
 void LayoutObject::invalidatePaintOfSubtreesIfNeeded(PaintInvalidationState& childPaintInvalidationState)
 {
+    ASSERT(!RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled());
+
     for (LayoutObject* child = slowFirstChild(); child; child = child->nextSibling()) {
         if (!child->isOutOfFlowPositioned())
             child->invalidateTreeIfNeeded(childPaintInvalidationState);
@@ -1393,7 +1391,6 @@ void LayoutObject::setPreviousSelectionRectForPaintInvalidation(const LayoutRect
         selectionPaintInvalidationMap->set(this, selectionRect);
 }
 
-// TODO(wangxianzhu): Remove this for slimming paint v2 because we won't care about paint invalidation rects.
 inline void LayoutObject::invalidateSelectionIfNeeded(const LayoutBoxModelObject& paintInvalidationContainer, const PaintInvalidationState& paintInvalidationState, PaintInvalidationReason invalidationReason)
 {
     // Update selection rect when we are doing full invalidation (in case that the object is moved, composite status changed, etc.)
@@ -1436,9 +1433,9 @@ PaintInvalidationReason LayoutObject::invalidatePaintIfNeeded(PaintInvalidationS
         return PaintInvalidationNone; // Don't invalidate paints if we're printing.
 
     const LayoutRect oldBounds = previousPaintInvalidationRect();
-    const LayoutPoint oldLocation = RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled() ? LayoutPoint() : previousPositionFromPaintInvalidationBacking();
+    const LayoutPoint oldLocation = previousPositionFromPaintInvalidationBacking();
     LayoutRect newBounds = boundsRectForPaintInvalidation(paintInvalidationContainer, &paintInvalidationState);
-    LayoutPoint newLocation = RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled() ? LayoutPoint() : PaintLayer::positionFromPaintInvalidationBacking(this, &paintInvalidationContainer, &paintInvalidationState);
+    LayoutPoint newLocation = PaintLayer::positionFromPaintInvalidationBacking(this, &paintInvalidationContainer, &paintInvalidationState);
 
     // Composited scrolling should not be included in the bounds and position tracking, because the graphics layer backing the scroller
     // does not move on scroll.
@@ -1449,8 +1446,7 @@ PaintInvalidationReason LayoutObject::invalidatePaintIfNeeded(PaintInvalidationS
     }
 
     setPreviousPaintInvalidationRect(newBounds);
-    if (!RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled())
-        setPreviousPositionFromPaintInvalidationBacking(newLocation);
+    setPreviousPositionFromPaintInvalidationBacking(newLocation);
 
     if (!shouldCheckForPaintInvalidationRegardlessOfPaintInvalidationState() && !paintInvalidationState.forcedSubtreeInvalidationWithinContainer()) {
         ASSERT(paintInvalidationState.forcedSubtreeInvalidationRectUpdateWithinContainer());
@@ -2630,6 +2626,11 @@ LayoutObject* LayoutObject::containerCrossingFrameBoundaries() const
     return isLayoutView() ? frame()->ownerLayoutObject() : container();
 }
 
+LayoutObject* LayoutObject::parentCrossingFrameBoundaries() const
+{
+    return isLayoutView() ? frame()->ownerLayoutObject() : parent();
+}
+
 bool LayoutObject::isSelectionBorder() const
 {
     SelectionState st = getSelectionState();
@@ -3445,6 +3446,14 @@ static PaintInvalidationReason documentLifecycleBasedPaintInvalidationReason(con
 
 inline void LayoutObject::markContainerChainForPaintInvalidation()
 {
+    if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled()) {
+        // We use PaintPropertyTreeBuilder, which walks layout tree in DOM order, for paint invalidation,
+        // so we need to mark paint invalidation flags also in DOM order (instead of containing block order).
+        for (LayoutObject* ancestor = this->parentCrossingFrameBoundaries(); ancestor && !ancestor->shouldCheckForPaintInvalidationRegardlessOfPaintInvalidationState(); ancestor = ancestor->parentCrossingFrameBoundaries())
+            ancestor->m_bitfields.setChildShouldCheckForPaintInvalidation(true);
+        return;
+    }
+
     for (LayoutObject* container = this->containerCrossingFrameBoundaries(); container && !container->shouldCheckForPaintInvalidationRegardlessOfPaintInvalidationState(); container = container->containerCrossingFrameBoundaries())
         container->m_bitfields.setChildShouldCheckForPaintInvalidation(true);
 }