Save previous paint offset in LayoutObject

third_party/WebKit/Source/core/paint/InlinePainter.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 "config.h"
 #include "core/paint/InlinePainter.h"
 
 #include "core/layout/LayoutBlock.h"
 #include "core/layout/LayoutInline.h"
 #include "core/layout/LayoutTheme.h"
 #include "core/layout/line/RootInlineBox.h"
 #include "core/paint/BoxPainter.h"
 #include "core/paint/LayoutObjectDrawingRecorder.h"
 #include "core/paint/LineBoxListPainter.h"
 #include "core/paint/ObjectPainter.h"
 #include "core/paint/PaintInfo.h"
 #include "platform/geometry/LayoutPoint.h"
 #include <limits>
 
 namespace blink {
 
 void InlinePainter::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
+    if (RuntimeEnabledFeatures::slimmingPaintOffsetCachingEnabled() && m_layoutInline.paintOffsetChanged(paintOffset))
+        LineBoxListPainter(*m_layoutInline.lineBoxes()).invalidateLineBoxPaintOffsets(paintInfo);
+
     // FIXME: When Skia supports annotation rect covering (https://code.google.com/p/skia/issues/detail?id=3872),
     // this rect may be covered by foreground and descendant drawings. Then we may need a dedicated paint phase.
     if (paintInfo.phase == PaintPhaseForeground && paintInfo.isPrinting())
         ObjectPainter(m_layoutInline).addPDFURLRectIfNeeded(paintInfo, paintOffset);
 
     if (paintInfo.phase == PaintPhaseOutline || paintInfo.phase == PaintPhaseSelfOutline || paintInfo.phase == PaintPhaseChildOutlines) {
         ObjectPainter painter(m_layoutInline);
         if (paintInfo.phase != PaintPhaseSelfOutline)
             painter.paintInlineChildrenOutlines(paintInfo, paintOffset);
         if (paintInfo.phase != PaintPhaseChildOutlines && !m_layoutInline.isElementContinuation())
             painter.paintOutline(paintInfo, paintOffset);
         return;
     }
 
     LineBoxListPainter(*m_layoutInline.lineBoxes()).paint(&m_layoutInline, paintInfo, paintOffset);
 }
 
 } // namespace blink