Move all fast-path paint invalidation mapping into PaintInvalidationState

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

Index: third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
diff --git a/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp b/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
index ca464ab93c3cb9394109bdd14c06d0e99660266c..78e56b6f47c7d13033fcd4d9342c25be077759d1 100644
--- a/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
+++ b/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
@@ -8,41 +8,54 @@
 #include "core/layout/LayoutView.h"
 #include "core/layout/svg/LayoutSVGModelObject.h"
 #include "core/layout/svg/LayoutSVGRoot.h"
+#include "core/layout/svg/SVGLayoutSupport.h"
 #include "core/paint/PaintLayer.h"
 
 namespace blink {
 
-PaintInvalidationState::PaintInvalidationState(const LayoutView& layoutView, Vector<LayoutObject*>& pendingDelayedPaintInvalidations, const PaintInvalidationState* ownerPaintInvalidationState)
+static LayoutSize computeViewPaintOffset(const LayoutView& layoutView, const LayoutBoxModelObject& paintInvalidationContainer)
+{
+    LayoutView::setViewClippingAndScrollOffsetDisabled(true);
+    FloatPoint point = layoutView.localToAncestorPoint(FloatPoint(), &paintInvalidationContainer, TraverseDocumentBoundaries);
+    LayoutView::setViewClippingAndScrollOffsetDisabled(false);
+    return LayoutSize(point.x(), point.y());
+}
+
+static bool supportsCachedOffsets(const LayoutObject& object)
+{
+    // TODO(wangxianzhu): Move some conditions to fast path if possible.
+    return !object.hasTransformRelatedProperty()
+        && !object.hasReflection()
+        && !object.hasFilter()
+        && object.styleRef().position() != FixedPosition;
+}
+
+static bool supportsCachedOffsetsForChildren(const LayoutObject& object)
+{
+    // TODO(wangxianzhu): Move some conditions to fast path if possible.
+    return !object.styleRef().isFlippedBlocksWritingMode()
+        && !object.isLayoutFlowThread();
+}
+
+PaintInvalidationState::PaintInvalidationState(const LayoutView& layoutView, Vector<LayoutObject*>& pendingDelayedPaintInvalidations)
     : m_currentObject(layoutView)
     , m_clipped(false)
     , m_cachedOffsetsEnabled(true)
     , m_forcedSubtreeInvalidationWithinContainer(false)
     , m_forcedSubtreeInvalidationRectUpdateWithinContainer(false)
-    , m_viewClippingAndScrollOffsetDisabled(false)
     , m_paintInvalidationContainer(layoutView.containerForPaintInvalidation())
     , m_pendingDelayedPaintInvalidations(pendingDelayedPaintInvalidations)
     , m_enclosingSelfPaintingLayer(*layoutView.layer())
 #if ENABLE(ASSERT)
-    , m_didUpdatePaintOffsetAndClipForChildren(true)
+    , m_didUpdateForChildren(false)
 #endif
 {
-    ASSERT(!ownerPaintInvalidationState || ownerPaintInvalidationState->m_didUpdatePaintOffsetAndClipForChildren);
-
-    bool establishesPaintInvalidationContainer = layoutView == m_paintInvalidationContainer;
-    if (!establishesPaintInvalidationContainer) {
-        if ((ownerPaintInvalidationState && !ownerPaintInvalidationState->m_cachedOffsetsEnabled)
-            || !layoutView.supportsPaintInvalidationStateCachedOffsets()) {
-            m_cachedOffsetsEnabled = false;
-            return;
-        }
-        if (ownerPaintInvalidationState && ownerPaintInvalidationState->m_forcedSubtreeInvalidationWithinContainer)
-            m_forcedSubtreeInvalidationWithinContainer = true;
-        FloatPoint point = layoutView.localToAncestorPoint(FloatPoint(), &m_paintInvalidationContainer, TraverseDocumentBoundaries);
-        m_paintOffset = LayoutSize(point.x(), point.y());
+    if (!supportsCachedOffsets(layoutView)) {
+        m_cachedOffsetsEnabled = false;
+        return;
     }
-    m_clipRect = layoutView.viewRect();
-    m_clipRect.move(m_paintOffset);
-    m_clipped = true;
+
+    m_paintOffset = computeViewPaintOffset(layoutView, m_paintInvalidationContainer);
 }
 
 // TODO(wangxianzhu): This is temporary for positioned object whose paintInvalidationContainer is different from
@@ -53,7 +66,6 @@ PaintInvalidationState::PaintInvalidationState(const PaintInvalidationState& par
     , m_cachedOffsetsEnabled(parentState.m_cachedOffsetsEnabled)
     , m_forcedSubtreeInvalidationWithinContainer(parentState.m_forcedSubtreeInvalidationWithinContainer)
     , m_forcedSubtreeInvalidationRectUpdateWithinContainer(parentState.m_forcedSubtreeInvalidationRectUpdateWithinContainer)
-    , m_viewClippingAndScrollOffsetDisabled(false)
     , m_clipRect(parentState.m_clipRect)
     , m_paintOffset(parentState.m_paintOffset)
     , m_paintInvalidationContainer(paintInvalidationContainer)
@@ -61,10 +73,10 @@ PaintInvalidationState::PaintInvalidationState(const PaintInvalidationState& par
     , m_pendingDelayedPaintInvalidations(parentState.pendingDelayedPaintInvalidationTargets())
     , m_enclosingSelfPaintingLayer(parentState.enclosingSelfPaintingLayer(currentObject))
 #if ENABLE(ASSERT)
-    , m_didUpdatePaintOffsetAndClipForChildren(true)
+    , m_didUpdateForChildren(true)
 #endif
 {
-    ASSERT(parentState.m_didUpdatePaintOffsetAndClipForChildren);
+    ASSERT(parentState.m_didUpdateForChildren);
     ASSERT(!m_cachedOffsetsEnabled);
 }
 
@@ -74,7 +86,6 @@ PaintInvalidationState::PaintInvalidationState(const PaintInvalidationState& par
     , m_cachedOffsetsEnabled(parentState.m_cachedOffsetsEnabled)
     , m_forcedSubtreeInvalidationWithinContainer(parentState.m_forcedSubtreeInvalidationWithinContainer)
     , m_forcedSubtreeInvalidationRectUpdateWithinContainer(parentState.m_forcedSubtreeInvalidationRectUpdateWithinContainer)
-    , m_viewClippingAndScrollOffsetDisabled(false)
     , m_clipRect(parentState.m_clipRect)
     , m_paintOffset(parentState.m_paintOffset)
     , m_paintInvalidationContainer(currentObject.isPaintInvalidationContainer() ? toLayoutBoxModelObject(currentObject) : parentState.m_paintInvalidationContainer)
@@ -82,34 +93,36 @@ PaintInvalidationState::PaintInvalidationState(const PaintInvalidationState& par
     , m_pendingDelayedPaintInvalidations(parentState.pendingDelayedPaintInvalidationTargets())
     , m_enclosingSelfPaintingLayer(parentState.enclosingSelfPaintingLayer(currentObject))
 #if ENABLE(ASSERT)
-    , m_didUpdatePaintOffsetAndClipForChildren(false)
+    , m_didUpdateForChildren(false)
 #endif
 {
-    ASSERT(parentState.m_didUpdatePaintOffsetAndClipForChildren);
-}
-
-void PaintInvalidationState::updatePaintOffsetAndClipForChildren()
-{
+    if (currentObject == parentState.m_currentObject) {
+        // Sometimes we create a new PaintInvalidationState from parentState on the same object.
+        // TODO(wangxianzhu): Avoid this for RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled().
 #if ENABLE(ASSERT)
-    ASSERT(!m_didUpdatePaintOffsetAndClipForChildren);
-    m_didUpdatePaintOffsetAndClipForChildren = true;
+        m_didUpdateForChildren = parentState.m_didUpdateForChildren;
 #endif
+        return;
+    }
+
+    ASSERT(parentState.m_didUpdateForChildren);
 
-    bool establishesPaintInvalidationContainer = m_currentObject == m_paintInvalidationContainer;
+    if (!currentObject.isBoxModelObject() && !currentObject.isSVG())
+        return;
+
+    bool establishesPaintInvalidationContainer = currentObject == m_paintInvalidationContainer;
 
-    if (!m_currentObject.isBoxModelObject()) {
+    if (currentObject.isSVG() && !currentObject.isSVGRoot()) {
         // TODO(wangxianzhu): SVG could probably benefit from a stack-based optimization like html does. crbug.com/391054.
-        ASSERT(m_currentObject.isSVG());
         ASSERT(!establishesPaintInvalidationContainer);
         if (m_cachedOffsetsEnabled)
-            m_svgTransform = AffineTransform(m_svgTransform * m_currentObject.localToSVGParentTransform());
+            m_svgTransform = AffineTransform(m_svgTransform * currentObject.localToSVGParentTransform());
         return;
     }
 
-    bool fixed = m_currentObject.style()->position() == FixedPosition;
-
-    if (!m_currentObject.supportsPaintInvalidationStateCachedOffsets())
+    if (!supportsCachedOffsets(currentObject))
         m_cachedOffsetsEnabled = false;
+
     if (establishesPaintInvalidationContainer) {
         // When we hit a new paint invalidation container, we don't need to
         // continue forcing a check for paint invalidation, since we're
@@ -120,67 +133,152 @@ void PaintInvalidationState::updatePaintOffsetAndClipForChildren()
 
         m_clipped = false; // Will be updated in applyClipIfNeeded().
         m_paintOffset = LayoutSize();
-    } else {
-        if (m_cachedOffsetsEnabled) {
-            if (fixed) {
-                FloatPoint fixedOffset = m_currentObject.localToAncestorPoint(FloatPoint(), &m_paintInvalidationContainer, TraverseDocumentBoundaries);
-                m_paintOffset = LayoutSize(fixedOffset.x(), fixedOffset.y());
-            } else if (m_currentObject.isBox() && !m_currentObject.isTableRow()) {
-                // We don't add locationOffset of table row because the child cells' location offsets include the row's location offset.
-                m_paintOffset += toLayoutBox(m_currentObject).locationOffset();
-            }
+    } else if (m_cachedOffsetsEnabled) {
+        if (currentObject.isLayoutView()) {
+            m_paintOffset = computeViewPaintOffset(toLayoutView(currentObject), m_paintInvalidationContainer);
+            return;
+        }
 
-            if (m_currentObject.isOutOfFlowPositioned() && !fixed) {
-                if (LayoutObject* container = m_currentObject.container()) {
-                    if (container->isInFlowPositioned() && container->isLayoutInline())
-                        m_paintOffset += toLayoutInline(container)->offsetForInFlowPositionedInline(toLayoutBox(m_currentObject));
-                }
+        if (currentObject.styleRef().position() == FixedPosition) {
+            // TODO(wangxianzhu): Replace localToAncestorPoint with fast path.
+            FloatPoint fixedOffset = currentObject.localToAncestorPoint(FloatPoint(), &m_paintInvalidationContainer, TraverseDocumentBoundaries);
+            m_paintOffset = LayoutSize(fixedOffset.x(), fixedOffset.y());
+            m_clipped = false;
+        } else if (currentObject.isBox()) {
+            m_paintOffset += toLayoutBox(currentObject).locationOffset();
+            if (currentObject.isTableCell()) {
+                // A table cell's locationOffset() includes its row's locationOffset().
+                m_paintOffset -= toLayoutBox(currentObject.parent())->locationOffset();
             }
+        }
 
-            if (m_currentObject.isInFlowPositioned() && m_currentObject.hasLayer())
-                m_paintOffset += toLayoutBoxModelObject(m_currentObject).layer()->offsetForInFlowPosition();
+        if (currentObject.styleRef().position() == AbsolutePosition) {
+            if (LayoutObject* container = currentObject.container()) {
+                if (container->isInFlowPositioned() && container->isLayoutInline())
+                    m_paintOffset += toLayoutInline(container)->offsetForInFlowPositionedInline(toLayoutBox(currentObject));
+            }
         }
 
-        m_clipped = !fixed && m_clipped;
+        if (currentObject.isInFlowPositioned() && currentObject.hasLayer())
+            m_paintOffset += toLayoutBoxModelObject(currentObject).layer()->offsetForInFlowPosition();
     }
 
-    if (m_cachedOffsetsEnabled && m_currentObject.isSVGRoot()) {
+    if (m_cachedOffsetsEnabled && currentObject.isSVGRoot())
+        m_svgTransform = AffineTransform(toLayoutSVGRoot(currentObject).localToBorderBoxTransform());
+}
+
+void PaintInvalidationState::updateForChildren()
+{
+#if ENABLE(ASSERT)
+    ASSERT(!m_didUpdateForChildren);
+    m_didUpdateForChildren = true;
+#endif
+
+    if (!m_cachedOffsetsEnabled)
+        return;
+
+    if (!supportsCachedOffsetsForChildren(m_currentObject)) {
+        m_cachedOffsetsEnabled = false;
+        return;
+    }
+
+    if (!m_currentObject.isBoxModelObject() && !m_currentObject.isSVG())
+        return;
+
+    if (m_currentObject.isLayoutView()) {
+        if (m_currentObject != m_paintInvalidationContainer) {
+            // TODO(wangxianzhu): Replace localToAncestorPoint with fast path.
+            FloatPoint viewOffset = m_currentObject.localToAncestorPoint(FloatPoint(), &m_paintInvalidationContainer, TraverseDocumentBoundaries);
+            m_paintOffset = LayoutSize(viewOffset.x(), viewOffset.y());
+            m_clipRect = toLayoutView(m_currentObject).viewRect();
+            m_clipRect.move(m_paintOffset);
+            m_clipped = true;
+            return;
+        }
+    } else if (m_currentObject.isSVGRoot()) {
         const LayoutSVGRoot& svgRoot = toLayoutSVGRoot(m_currentObject);
-        m_svgTransform = AffineTransform(svgRoot.localToBorderBoxTransform());
         if (svgRoot.shouldApplyViewportClip())
             addClipRectRelativeToPaintOffset(LayoutSize(svgRoot.pixelSnappedSize()));
     }
 
-    applyClipIfNeeded();
+    if (!m_currentObject.hasOverflowClip())
+        return;
+
+    const LayoutBox& box = toLayoutBox(m_currentObject);
+
+    // Do not clip scroll layer contents because the compositor expects the whole layer
+    // to be always invalidated in-time.
+    if (box.usesCompositedScrolling())
+        ASSERT(!m_clipped); // The box should establish paint invalidation container, so no m_clipped inherited.
+    else
+        addClipRectRelativeToPaintOffset(LayoutSize(box.layer()->size()));
+
+    m_paintOffset -= box.scrolledContentOffset();
 
     // FIXME: <http://bugs.webkit.org/show_bug.cgi?id=13443> Apply control clip if present.
 }
 
-void PaintInvalidationState::mapObjectRectToAncestor(const LayoutObject& object, const LayoutBoxModelObject* ancestor, LayoutRect& rect) const
+LayoutPoint PaintInvalidationState::computePositionFromPaintInvalidationBacking() const
 {
-    ASSERT(canMapToAncestor(ancestor));
-
-    if (ancestor == &object) {
-        if (object.isBox() && object.styleRef().isFlippedBlocksWritingMode())
-            toLayoutBox(object).flipForWritingMode(rect);
-        return;
+    FloatPoint point;
+    if (m_paintInvalidationContainer != m_currentObject) {
+        if (m_cachedOffsetsEnabled) {
+            if (m_currentObject.isSVG() && !m_currentObject.isSVGRoot())
+                point = m_svgTransform.mapPoint(point);
+            point += FloatPoint(m_paintOffset);
+        } else {
+            // Fallback to slow path.
+            point = m_currentObject.localToAncestorPoint(FloatPoint(), &m_paintInvalidationContainer);
+        }
     }
 
-    if (object.hasLayer()) {
-        if (const TransformationMatrix* transform = toLayoutBoxModelObject(object).layer()->transform())
-            rect = LayoutRect(transform->mapRect(pixelSnappedIntRect(rect)));
+    if (m_paintInvalidationContainer.layer()->groupedMapping())
+        PaintLayer::mapPointInPaintInvalidationContainerToBacking(m_paintInvalidationContainer, point);
+
+    return LayoutPoint(point);
+}
+
+LayoutRect PaintInvalidationState::computePaintInvalidationRectInBacking() const
+{
+    if (m_currentObject.isSVG() && !m_currentObject.isSVGRoot())
+        return computePaintInvalidationRectInBackingForSVG();
+
+    LayoutRect rect = m_currentObject.localOverflowRectForPaintInvalidation();
+    mapLocalRectToPaintInvalidationBacking(rect);
+    return rect;
+}
 
-        if (object.isInFlowPositioned())
-            rect.move(toLayoutBoxModelObject(object).layer()->offsetForInFlowPosition());
+LayoutRect PaintInvalidationState::computePaintInvalidationRectInBackingForSVG() const
+{
+    LayoutRect rect;
+    if (m_cachedOffsetsEnabled) {
+        FloatRect svgRect = SVGLayoutSupport::localOverflowRectForPaintInvalidation(m_currentObject);
+        rect = SVGLayoutSupport::transformPaintInvalidationRect(m_currentObject, m_svgTransform, svgRect);
+        rect.move(m_paintOffset);
+        if (m_clipped)
+            rect.intersect(m_clipRect);
+    } else {
+        rect = SVGLayoutSupport::clippedOverflowRectForPaintInvalidation(m_currentObject, m_paintInvalidationContainer);
     }
 
-    if (object.isBox())
-        rect.moveBy(toLayoutBox(object).location());
+    if (m_paintInvalidationContainer.layer()->groupedMapping())
+        PaintLayer::mapRectInPaintInvalidationContainerToBacking(m_paintInvalidationContainer, rect);
+    return rect;
+}
 
-    rect.move(m_paintOffset);
+void PaintInvalidationState::mapLocalRectToPaintInvalidationBacking(LayoutRect& rect) const
+{
+    if (m_cachedOffsetsEnabled) {
+        rect.move(m_paintOffset);
+        if (m_clipped)
+            rect.intersect(m_clipRect);
+    } else {
+        // Fallback to slow path.
+        m_currentObject.mapToVisibleRectInAncestorSpace(&m_paintInvalidationContainer, rect);
+    }
 
-    if (m_clipped)
-        rect.intersect(m_clipRect);
+    if (m_paintInvalidationContainer.layer()->groupedMapping())
+        PaintLayer::mapRectInPaintInvalidationContainerToBacking(m_paintInvalidationContainer, rect);
 }
 
 void PaintInvalidationState::addClipRectRelativeToPaintOffset(const LayoutSize& clipSize)
@@ -194,23 +292,6 @@ void PaintInvalidationState::addClipRectRelativeToPaintOffset(const LayoutSize&
     }
 }
 
-void PaintInvalidationState::applyClipIfNeeded()
-{
-    if (!m_currentObject.hasOverflowClip())
-        return;
-
-    const LayoutBox& box = toLayoutBox(m_currentObject);
-
-    // Do not clip scroll layer contents because the compositor expects the whole layer
-    // to be always invalidated in-time.
-    if (box.usesCompositedScrolling())
-        ASSERT(!m_clipped); // The box should establish paint invalidation container, so no m_clipped inherited.
-    else
-        addClipRectRelativeToPaintOffset(LayoutSize(box.layer()->size()));
-
-    m_paintOffset -= box.scrolledContentOffset();
-}
-
 PaintLayer& PaintInvalidationState::enclosingSelfPaintingLayer(const LayoutObject& layoutObject) const
 {
     if (layoutObject.hasLayer() && toLayoutBoxModelObject(layoutObject).hasSelfPaintingLayer())