Move squash preventing reasons out of compositing reasons

third_party/WebKit/Source/core/paint/PaintLayer.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayer.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayer.cpp b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
index 439349d2394c2004de69919ece04374bd32dfaf6..6c78b422c86724b702e558041cfb10d4b95d86a3 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
@@ -124,6 +124,7 @@ PaintLayerRareData::PaintLayerRareData()
     : enclosingPaginationLayer(nullptr)
     , potentialCompositingReasonsFromStyle(CompositingReasonNone)
     , compositingReasons(CompositingReasonNone)
+    , squashingDisallowedReasons(SquashingDisallowedReasonsNone)
     , groupedMapping(nullptr)
 {
 }
@@ -1032,6 +1033,15 @@ void PaintLayer::setCompositingReasons(CompositingReasons reasons, CompositingRe
         ensureRareData().compositingReasons = newReasons;
 }
 
+void PaintLayer::setSquashingDisallowedReasons(SquashingDisallowedReasons reasons)
+{
+    SquashingDisallowedReasons oldReasons = m_rareData ? m_rareData->squashingDisallowedReasons : SquashingDisallowedReasonsNone;
+    if (oldReasons == reasons)
+        return;
+    if (m_rareData || reasons != SquashingDisallowedReasonsNone)
+        ensureRareData().squashingDisallowedReasons = reasons;
+}
+
 void PaintLayer::setHasCompositingDescendant(bool hasCompositingDescendant)
 {
     if (m_hasCompositingDescendant == static_cast<unsigned>(hasCompositingDescendant))