Merge image sizing algorithms

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 118 matching lines @@
         return;
     if (m_layoutBox.backgroundStolenForBeingBody())
         return;
     if (m_layoutBox.boxDecorationBackgroundIsKnownToBeObscured())
         return;
     paintFillLayers(paintInfo, backgroundColor, m_layoutBox.style()->backgroundLayers(), paintRect, bleedAvoidance);
 }
 
 bool BoxPainter::isFillLayerOpaque(const FillLayer& layer, const LayoutObject& imageClient)
 {
+    // The default object size passed down to imageSize is empty with the implication that images
+    // with no intrinsic size are treated as empty.
     return layer.hasOpaqueImage(&imageClient)
         && layer.image()->canRender()
-        && !layer.image()->imageSize(&imageClient, imageClient.style()->effectiveZoom()).isEmpty()
+        && !layer.image()->imageSize(&imageClient, imageClient.style()->effectiveZoom(), LayoutSize()).isEmpty()

[fs, 2016/03/03 15:22:53]

Not your doing, and no action necessarily required, but in many cases
canRender() above will end up in ImageResource::canRender which checks this
predicate - just without the default object size. So I'm guessing that we'd
rather want to be able to use canRender() alone to determine this (I'm guessing
it won't work though because not all subclasses implement the method in a
compatible manner AFAICS.)

Regardless though, passing effective zoom seems redundant.

[davve, 2016/03/04 06:49:43]

Good observation. Using canRender() alone would be the reasonable thing here.
I'll queue a CL for getting this of at least this part.

         && layer.hasRepeatXY();
 }
 
 bool BoxPainter::calculateFillLayerOcclusionCulling(FillLayerOcclusionOutputList &reversedPaintList, const FillLayer& fillLayer)
 {
     bool isNonAssociative = false;
     for (auto currentLayer = &fillLayer; currentLayer; currentLayer = currentLayer->next()) {
         reversedPaintList.append(currentLayer);
         // Stop traversal when an opaque layer is encountered.
         // FIXME : It would be possible for the following occlusion culling test to be more aggressive
@@ skipping 538 matching lines @@
     }
 }
 
 bool BoxPainter::shouldForceWhiteBackgroundForPrintEconomy(const ComputedStyle& style, const Document& document)
 {
     return document.printing() && style.printColorAdjust() == PrintColorAdjustEconomy
         && (!document.settings() || !document.settings()->shouldPrintBackgrounds());
 }
 
 } // namespace blink