[SPInvalidation] Don't apply FrameView content clip and scroll on LayoutView

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/PaintInvalidator.h"
 
 #include "core/editing/FrameSelection.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
@@ skipping 148 matching lines @@
         context.paintingLayer->setNeedsPaintPhaseDescendantBlockBackgrounds();
     }
 
     if (object.isTable()) {
         const LayoutTable& table = toLayoutTable(object);
         if (table.collapseBorders() && !table.collapsedBorders().isEmpty())
             context.paintingLayer->setNeedsPaintPhaseDescendantBlockBackgrounds();
     }
 }
 
+namespace {
+
+// This is temporary to workaround paint invalidation issues in non-rootLayerScrolls mode.
+// It undos FrameView's content clip and scroll for paint invalidation of frame
+// scroll controls and the LayoutView to which the content clip and scroll don't apply.
+class ScopedUndoFrameViewContentClipAndScroll {
+public:
+    ScopedUndoFrameViewContentClipAndScroll(const FrameView& frameView, PaintInvalidatorContext& context)
+        : m_treeBuilderContext(const_cast<PaintPropertyTreeBuilderContext&>(context.treeBuilderContext))
+        , m_savedContext(m_treeBuilderContext.current)
+    {
+        DCHECK(!RuntimeEnabledFeatures::rootLayerScrollingEnabled());
+
+        if (frameView.contentClip() == m_savedContext.clip)
+            m_treeBuilderContext.current.clip = m_savedContext.clip->parent();
+        if (frameView.scroll() == m_savedContext.scroll)
+            m_treeBuilderContext.current.scroll = m_savedContext.scroll->parent();
+        if (frameView.scrollTranslation() == m_savedContext.transform)
+            m_treeBuilderContext.current.transform = m_savedContext.transform->parent();
+    }
+
+    ~ScopedUndoFrameViewContentClipAndScroll()
+    {
+        m_treeBuilderContext.current = m_savedContext;
+    }
+
+private:
+    PaintPropertyTreeBuilderContext& m_treeBuilderContext;
+    PaintPropertyTreeBuilderContext::ContainingBlockContext m_savedContext;
+};
+
+} // namespace
+
 void PaintInvalidator::updateContext(const LayoutObject& object, PaintInvalidatorContext& context)
 {
+    Optional<ScopedUndoFrameViewContentClipAndScroll> undoFrameViewContentClipAndScroll;
+
     if (object.isPaintInvalidationContainer()) {
         context.paintInvalidationContainer = toLayoutBoxModelObject(&object);
         if (object.styleRef().isStackingContext())
             context.paintInvalidationContainerForStackedContents = toLayoutBoxModelObject(&object);
     } else if (object.isLayoutView()) {
         // paintInvalidationContainerForStackedContents is only for stacked descendants in its own frame,
         // because it doesn't establish stacking context for stacked contents in sub-frames.
         // Contents stacked in the root stacking context in this frame should use this frame's paintInvalidationContainer.
         context.paintInvalidationContainerForStackedContents = context.paintInvalidationContainer;
+        if (!RuntimeEnabledFeatures::rootLayerScrollingEnabled())
+            undoFrameViewContentClipAndScroll.emplace(*toLayoutView(object).frameView(), context);
     } else if (object.styleRef().isStacked()
         // This is to exclude some objects (e.g. LayoutText) inheriting stacked style from parent but aren't actually stacked.
         && object.hasLayer()
         && context.paintInvalidationContainer != context.paintInvalidationContainerForStackedContents) {
         // The current object is stacked, so we should use m_paintInvalidationContainerForStackedContents as its
         // paint invalidation container on which the current object is painted.
         context.paintInvalidationContainer = context.paintInvalidationContainerForStackedContents;
         if (context.forcedSubtreeInvalidationFlags & PaintInvalidatorContext::ForcedSubtreeFullInvalidationForStackedContents)
             context.forcedSubtreeInvalidationFlags |= PaintInvalidatorContext::ForcedSubtreeFullInvalidation;
     }
@@ skipping 38 matching lines @@
 
 void PaintInvalidator::invalidatePaintIfNeeded(FrameView& frameView, PaintInvalidatorContext& context)
 {
     LayoutView* layoutView = frameView.layoutView();
     CHECK(layoutView);
 
     context.paintInvalidationContainer = context.paintInvalidationContainerForStackedContents = &layoutView->containerForPaintInvalidation();
     context.paintingLayer = layoutView->layer();
 
     if (!RuntimeEnabledFeatures::rootLayerScrollingEnabled()) {
-        // Undo content clip and scroll before invalidating FrameView scrollbars.
-        PaintPropertyTreeBuilderContext& treeBuilderContext = const_cast<PaintPropertyTreeBuilderContext&>(context.treeBuilderContext);
-        PaintPropertyTreeBuilderContext::ContainingBlockContext savedCurrent = treeBuilderContext.current;
-        if (frameView.contentClip() == savedCurrent.clip)
-            treeBuilderContext.current.clip =  savedCurrent.clip->parent();
-        if (frameView.scroll() == savedCurrent.scroll)
-            treeBuilderContext.current.scroll = savedCurrent.scroll->parent();
-        if (frameView.scrollTranslation() == savedCurrent.transform)
-            treeBuilderContext.current.transform = savedCurrent.transform->parent();
+        ScopedUndoFrameViewContentClipAndScroll undo(frameView, context);
         frameView.invalidatePaintOfScrollControlsIfNeeded(context);
-        treeBuilderContext.current = savedCurrent;
     }
 
     if (frameView.frame().selection().isCaretBoundsDirty())
         frameView.frame().selection().invalidateCaretRect();
 
     // Temporary callback for crbug.com/487345,402044
     // TODO(ojan): Make this more general to be used by PositionObserver
     // and rAF throttling.
     IntRect visibleRect = frameView.rootFrameToContents(frameView.computeVisibleArea());
     layoutView->sendMediaPositionChangeNotifications(visibleRect);
@@ skipping 65 matching lines @@
     object.getMutableForPainting().clearPaintInvalidationFlags();
 }
 
 void PaintInvalidator::processPendingDelayedPaintInvalidations()
 {
     for (auto target : m_pendingDelayedPaintInvalidations)
         target->getMutableForPainting().setShouldDoFullPaintInvalidation(PaintInvalidationDelayedFull);
 }
 
 } // namespace blink