WIP: Skeleton for paint offset caching

Source/core/paint/BoxPainter.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/BoxPainter.h"
 
 #include "core/HTMLNames.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLFrameOwnerElement.h"
@@ skipping 68 matching lines @@
 void BoxPainter::paintBoxDecorationBackgroundWithRect(const PaintInfo& paintInfo, const LayoutPoint& paintOffset, const LayoutRect& paintRect)
 {
     const ComputedStyle& style = m_layoutBox.styleRef();
 
     // FIXME: For now we don't have notification on media buffered range change from media player
     // and miss paint invalidation on buffered range change. crbug.com/484288.
     Optional<DisplayItemCacheSkipper> cacheSkipper;
     if (style.appearance() == MediaSliderPart)
         cacheSkipper.emplace(*paintInfo.context);
 
-    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutBox, DisplayItem::BoxDecorationBackground))
+    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutBox, DisplayItem::BoxDecorationBackground, paintOffset))
         return;
 
-    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutBox, DisplayItem::BoxDecorationBackground, boundsForDrawingRecorder(paintOffset));
+    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutBox, DisplayItem::BoxDecorationBackground, boundsForDrawingRecorder(paintOffset), paintOffset);
 
     BoxDecorationData boxDecorationData(m_layoutBox);
 
     // FIXME: Should eventually give the theme control over whether the box shadow should paint, since controls could have
     // custom shadows of their own.
     if (!m_layoutBox.boxShadowShouldBeAppliedToBackground(boxDecorationData.bleedAvoidance))
         paintBoxShadow(paintInfo, paintRect, style, Normal);
 
     GraphicsContextStateSaver stateSaver(*paintInfo.context, false);
     if (bleedAvoidanceIsClipping(boxDecorationData.bleedAvoidance)) {
@@ skipping 401 matching lines @@
         context->endLayer();
         context->endLayer();
     }
 }
 
 void BoxPainter::paintMask(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     if (!paintInfo.shouldPaintWithinRoot(&m_layoutBox) || m_layoutBox.style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseMask)
         return;
 
-    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutBox, paintInfo.phase))
+    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutBox, paintInfo.phase, paintOffset))
         return;
 
     LayoutRect visualOverflowRect(m_layoutBox.visualOverflowRect());
     visualOverflowRect.moveBy(paintOffset);
 
-    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutBox, paintInfo.phase, visualOverflowRect);
+    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutBox, paintInfo.phase, visualOverflowRect, paintOffset);
     LayoutRect paintRect = LayoutRect(paintOffset, m_layoutBox.size());
     paintMaskImages(paintInfo, paintRect);
 }
 
 void BoxPainter::paintMaskImages(const PaintInfo& paintInfo, const LayoutRect& paintRect)
 {
     // Figure out if we need to push a transparency layer to render our mask.
     bool pushTransparencyLayer = false;
     bool compositedMask = m_layoutBox.hasLayer() && m_layoutBox.layer()->hasCompositedMask();
     bool flattenCompositingLayers = paintInfo.globalPaintFlags() & GlobalPaintFlattenCompositingLayers;
@@ skipping 26 matching lines @@
 void BoxPainter::paintClippingMask(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     ASSERT(paintInfo.phase == PaintPhaseClippingMask);
 
     if (!paintInfo.shouldPaintWithinRoot(&m_layoutBox) || m_layoutBox.style()->visibility() != VISIBLE)
         return;
 
     if (!m_layoutBox.layer() || m_layoutBox.layer()->compositingState() != PaintsIntoOwnBacking)
         return;
 
-    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutBox, paintInfo.phase))
+    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutBox, paintInfo.phase, paintOffset))
         return;
 
     IntRect paintRect = pixelSnappedIntRect(LayoutRect(paintOffset, m_layoutBox.size()));
-    LayoutObjectDrawingRecorder drawingRecorder(*paintInfo.context, m_layoutBox, paintInfo.phase, paintRect);
+    LayoutObjectDrawingRecorder drawingRecorder(*paintInfo.context, m_layoutBox, paintInfo.phase, paintRect, paintOffset);
     paintInfo.context->fillRect(paintRect, Color::black);
 }
 
 InterpolationQuality BoxPainter::chooseInterpolationQuality(LayoutObject& obj, GraphicsContext* context, Image* image, const void* layer, const LayoutSize& size)
 {
     return ImageQualityController::imageQualityController()->chooseInterpolationQuality(context, &obj, image, layer, size);
 }
 
 bool BoxPainter::paintNinePieceImage(LayoutBoxModelObject& obj, GraphicsContext* graphicsContext, const LayoutRect& rect, const ComputedStyle& style, const NinePieceImage& ninePieceImage, SkXfermode::Mode op)
 {
@@ skipping 180 matching lines @@
     }
 }
 
 bool BoxPainter::shouldForceWhiteBackgroundForPrintEconomy(const ComputedStyle& style, const Document& document)
 {
     return document.printing() && style.printColorAdjust() == PrintColorAdjustEconomy
         && (!document.settings() || !document.settings()->shouldPrintBackgrounds());
 }
 
 } // namespace blink