Implement the framework for the paint property hierarchy

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 7bdb735193ca2461f26b4bd57ee7f2a799a1acd1..91d3f3253d71f6165621686315dcbf7418c2e0b1 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
@@ -72,6 +72,7 @@
 #include "core/page/Page.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/paint/FilterEffectBuilder.h"
+#include "core/paint/ObjectPaintProperties.h"
 #include "platform/LengthFunctions.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/TraceEvent.h"
@@ -2714,6 +2715,20 @@ void PaintLayer::markAncestorChainForNeedsRepaint()
     }
 }
 
+void PaintLayer::setPaintProperties(PassOwnPtr<ObjectPaintProperties> paintProperties)

[jbroman, 2015/10/07 15:22:22]

nit: I'd rather the caller be able to update the existing ObjectPaintProperties
instance (e.g. using the rare-data ensurePaintProperties() pattern or similar),
to avoid doing a ton of alloc/dealloc pairs when updating these.

This might be premature optimization, so we can leave this to later if you'd
prefer.

[pdr., 2015/10/07 20:19:11]

Done. Changed to non-const mutablePaintProperties() and const paintProperties().

+{
+    ASSERT(RuntimeEnabledFeatures::slimmingPaintV2Enabled());
+    ASSERT(layoutObject()->document().lifecycle().state() == DocumentLifecycle::InUpdatePaintProperties);
+    m_paintProperties = paintProperties;
+}
+
+const ObjectPaintProperties* PaintLayer::paintProperties() const
+{
+    ASSERT(RuntimeEnabledFeatures::slimmingPaintV2Enabled());
+    ASSERT(layoutObject()->document().lifecycle().state() == DocumentLifecycle::InPaint);
+    return m_paintProperties.get();
+}
+
 DisableCompositingQueryAsserts::DisableCompositingQueryAsserts()
     : m_disabler(gCompositingQueryMode, CompositingQueriesAreAllowed) { }