Allocate a drawing recorder locally to BoxPainter code in the mask phase.

Source/core/paint/BoxPainter.cpp

Index: Source/core/paint/BoxPainter.cpp
diff --git a/Source/core/paint/BoxPainter.cpp b/Source/core/paint/BoxPainter.cpp
index 160934f6c864c0aa4a631263a67ee4fc20b294f3..ceb004bef5a509b98bd38200bf42bf310e23299c 100644
--- a/Source/core/paint/BoxPainter.cpp
+++ b/Source/core/paint/BoxPainter.cpp
@@ -519,9 +519,14 @@ void BoxPainter::paintFillLayerExtended(LayoutBoxModelObject& obj, const PaintIn
 
 void BoxPainter::paintMask(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
+    LayoutRect visualOverflowRect(m_layoutBox.visualOverflowRect());
+    visualOverflowRect.moveBy(paintOffset);
+
+    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutBox, paintInfo.phase, visualOverflowRect);
+    if (recorder.canUseCachedDrawing())

[wkorman, 2015/06/19 23:20:43]

Could also just add this to the three bail-out conditionals we've already got on
line 528 but perhaps having separate is clearer, fine either way.

[chrishtr, 2015/06/20 02:22:45]

I prefer separate, to make it clear we are checking for caching.

+        return;
     if (!paintInfo.shouldPaintWithinRoot(&m_layoutBox) || m_layoutBox.style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseMask)
         return;
-
     LayoutRect paintRect = LayoutRect(paintOffset, m_layoutBox.size());
     paintMaskImages(paintInfo, paintRect);
 }