Fix visual rect for background box painting in composited scrollers.

third_party/WebKit/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 "core/paint/BoxPainter.h"
 
 #include "core/HTMLNames.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "core/layout/ImageQualityController.h"
@@ skipping 88 matching lines @@
 } // anonymous namespace
 
 void BoxPainter::paintBoxDecorationBackgroundWithRect(const PaintInfo& paintInfo, const LayoutPoint& paintOffset, const LayoutRect& paintRect)
 {
     bool paintingOverflowContents = isPaintingBackgroundOfPaintContainerIntoScrollingContentsLayer(&m_layoutBox, paintInfo);
     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)
+    if (style.appearance() == MediaSliderPart
+        // We may paint a delayed-invalidation object before it's actually invalidated. Note this would be handled for

[chrishtr, 2016/08/22 17:34:54]

Really? Which test failed without line 113?

[wkorman, 2016/08/22 17:42:27]

paint/invalidation/animated-gif-background-offscreen.html

[chrishtr, 2016/08/22 17:46:33]

ok.

+        // us by LayoutObjectDrawingRecorder but we have to use DrawingRecorder as we may use the scrolling contents
+        // layer as DisplayItemClient below.
+        || m_layoutBox.fullPaintInvalidationReason() == PaintInvalidationDelayedFull) {
         cacheSkipper.emplace(paintInfo.context);
+    }
 
-    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(paintInfo.context, m_layoutBox, DisplayItem::BoxDecorationBackground))
+    const DisplayItemClient& displayItemClient = paintingOverflowContents ? static_cast<const DisplayItemClient&>(*m_layoutBox.layer()->compositedLayerMapping()->scrollingContentsLayer()) : m_layoutBox;
+    if (DrawingRecorder::useCachedDrawingIfPossible(paintInfo.context, displayItemClient, DisplayItem::BoxDecorationBackground))
         return;
 
-    LayoutObjectDrawingRecorder recorder(paintInfo.context, m_layoutBox, DisplayItem::BoxDecorationBackground, boundsForDrawingRecorder(paintInfo, paintOffset));
-
+    DrawingRecorder recorder(paintInfo.context, displayItemClient, DisplayItem::BoxDecorationBackground, FloatRect(boundsForDrawingRecorder(paintInfo, paintOffset)));
     BoxDecorationData boxDecorationData(m_layoutBox);
     GraphicsContextStateSaver stateSaver(paintInfo.context, false);
 
     if (!paintingOverflowContents) {
         // 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);
         }
 
@@ skipping 735 matching lines @@
     }
 }
 
 bool BoxPainter::shouldForceWhiteBackgroundForPrintEconomy(const ComputedStyle& style, const Document& document)
 {
     return document.printing() && style.getPrintColorAdjust() == PrintColorAdjustEconomy
         && (!document.settings() || !document.settings()->shouldPrintBackgrounds());
 }
 
 } // namespace blink