Move LayoutObject::m_previousPosition... into a global map in ObjectPaintInvalidator

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 5153efde1d23c2c9080d506d21f49853ef941b9e..785816f5a992c2e24e94d9f04f2753b2e887ad88 100644
--- a/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
+++ b/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
@@ -409,12 +409,17 @@ static FloatPoint slowLocalToAncestorPoint(const LayoutObject& object,
   return result;
 }
 
-LayoutPoint
-PaintInvalidationState::computePositionFromPaintInvalidationBacking() const {
+LayoutPoint PaintInvalidationState::computeLocationInBacking(
+    const LayoutPoint& visualRectLocation) const {
 #if ENABLE(ASSERT)
   DCHECK(!m_didUpdateForChildren);
 #endif
 
+  // Use visual rect location for LayoutTexts because it suffices to check
+  // visual rect change for layout caused invalidation.
+  if (m_currentObject.isText())
+    return visualRectLocation;
+
   FloatPoint point;
   if (m_paintInvalidationContainer != &m_currentObject) {
     if (m_cachedOffsetsEnabled) {
@@ -422,7 +427,9 @@ PaintInvalidationState::computePositionFromPaintInvalidationBacking() const {
         point = m_svgTransform.mapPoint(point);
       point += FloatPoint(m_paintOffset);
 #ifdef CHECK_FAST_PATH_SLOW_PATH_EQUALITY
-            DCHECK(point == slowLocalOriginToAncestorPoint(m_currentObject, m_paintInvalidationContainer, FloatPoint());
+      DCHECK(point ==
+             slowLocalOriginToAncestorPoint(
+                 m_currentObject, m_paintInvalidationContainer, FloatPoint()));
 #endif
     } else {
       point = slowLocalToAncestorPoint(