Revert of Replace LayoutObject::skipInvalidationWhenLaidOutChildren() with painted...

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 fbabc29e7b06f7f541940ce688346a2b305aa2e4..78d02a87c11a1c59fab1f61efe381b2dd8aebd62 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
@@ -684,6 +684,28 @@
     return LayoutFlowThread::locateFlowThreadContainingBlockOf(*this);
 }
 
+bool LayoutObject::skipInvalidationWhenLaidOutChildren() const
+{
+    if (!m_bitfields.neededLayoutBecauseOfChildren())
+        return false;
+
+    // SVG layoutObjects need to be invalidated when their children are laid out.
+    // LayoutBlocks with line boxes are responsible to invalidate them so we can't ignore them.
+    if (isSVG() || (isLayoutBlockFlow() && toLayoutBlockFlow(this)->firstLineBox()))
+        return false;
+
+    // In case scrollbars got repositioned (which will typically happen if the layout object got
+    // resized), we cannot skip invalidation.
+    if (hasNonCompositedScrollbars())
+        return false;
+
+    // We can't detect whether a plugin has box effects, so disable this optimization for that case.
+    if (isEmbeddedObject())
+        return false;
+
+    return !hasBoxEffect();
+}
+
 static inline bool objectIsRelayoutBoundary(const LayoutObject* object)
 {
     // FIXME: In future it may be possible to broaden these conditions in order to improve performance.
@@ -1308,6 +1330,7 @@
         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.)
@@ -1331,10 +1354,11 @@
 
     setPreviousSelectionRectForPaintInvalidation(newSelectionRect);
 
-    if (!fullInvalidation) {
+    // TODO(wangxianzhu): Combine the following two conditions when removing LayoutView::doingFullPaintInvalidation().
+    if (!fullInvalidation)
         fullyInvalidatePaint(paintInvalidationContainer, PaintInvalidationSelection, oldSelectionRect, newSelectionRect);
+    if (shouldInvalidateSelection())
         invalidateDisplayItemClientsWithPaintInvalidationState(paintInvalidationState, PaintInvalidationSelection);
-    }
 }
 
 PaintInvalidationReason LayoutObject::invalidatePaintIfNeeded(const PaintInvalidationState& paintInvalidationState)
@@ -1399,7 +1423,7 @@
         // invalidation is issued. See crbug.com/508383 and crbug.com/515977.
         // This is a workaround to force display items to update paint offset.
         if (!RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled() && paintInvalidationState.forcedSubtreeInvalidationCheckingWithinContainer())
-            invalidateDisplayItemClientsWithPaintInvalidationState(paintInvalidationState, PaintInvalidationLocationChange);
+            invalidateDisplayItemClientsWithPaintInvalidationState(paintInvalidationState, invalidationReason);
 
         return invalidationReason;
     }
@@ -1422,9 +1446,6 @@
 
     if (shouldDoFullPaintInvalidation())
         return m_bitfields.fullPaintInvalidationReason();
-
-    if (paintedOutputOfObjectHasNoEffect())
-        return PaintInvalidationNone;
 
     // The outline may change shape because of position change of descendants. For simplicity,
     // just force full paint invalidation if this object is marked for checking paint invalidation
@@ -1443,6 +1464,13 @@
     // be caused by some layout property (left / top) or some in-flow layoutObject inserted / removed before us in the tree.
     if (newBounds.location() != oldBounds.location())
         return PaintInvalidationBoundsChange;
+
+    // This covers the case where we mark containing blocks for layout
+    // and they change size but don't have anything to paint. This is
+    // a pretty common case for <body> as we add / remove children
+    // (and the default background is done by FrameView).
+    if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled() && skipInvalidationWhenLaidOutChildren())
+        return PaintInvalidationNone;
 
     // If the size is zero on one of our bounds then we know we're going to have
     // to do a full invalidation of either old bounds or new bounds. If we fall
@@ -3430,6 +3458,7 @@
     ASSERT(!shouldCheckForPaintInvalidationRegardlessOfPaintInvalidationState() || paintInvalidationStateIsDirty());
     clearShouldDoFullPaintInvalidation();
     m_bitfields.setChildShouldCheckForPaintInvalidation(false);
+    m_bitfields.setNeededLayoutBecauseOfChildren(false);
     m_bitfields.setMayNeedPaintInvalidation(false);
     m_bitfields.setMayNeedPaintInvalidationSubtree(false);
     m_bitfields.setShouldInvalidateSelection(false);