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

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

 // Copyright 2014 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/layout/PaintInvalidationState.h"
 
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
 #include "core/layout/LayoutInline.h"
@@ skipping 391 matching lines @@
       object.localToAncestorPoint(point, &ancestor, TraverseDocumentBoundaries);
   // Paint invalidation does not include scroll of the ancestor.
   if (ancestor.isBox()) {
     const LayoutBox* box = toLayoutBox(&ancestor);
     if (box->hasOverflowClip())
       result.move(box->scrolledContentOffset());
   }
   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) {
       if (m_currentObject.isSVG() && !m_currentObject.isSVGRoot())
         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(
           m_currentObject, *m_paintInvalidationContainer, FloatPoint());
     }
   }
 
   if (m_paintInvalidationContainer->layer()->groupedMapping())
     PaintLayer::mapPointInPaintInvalidationContainerToBacking(
         *m_paintInvalidationContainer, point);
@@ skipping 184 matching lines @@
 }
 
 void PaintInvalidatorContextAdapter::mapLocalRectToPaintInvalidationBacking(
     const LayoutObject& object,
     LayoutRect& rect) const {
   DCHECK(&object == &m_paintInvalidationState.currentObject());
   m_paintInvalidationState.mapLocalRectToPaintInvalidationBacking(rect);
 }
 
 }  // namespace blink