Add a document phase for calculating paint properties

third_party/WebKit/Source/core/frame/FrameView.cpp

Index: third_party/WebKit/Source/core/frame/FrameView.cpp
diff --git a/third_party/WebKit/Source/core/frame/FrameView.cpp b/third_party/WebKit/Source/core/frame/FrameView.cpp
index f4e95cddf6821a06dfddb47f966c923a26c34bdc..98c3b767859b51fafa812deac8139546fc45173a 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -2437,6 +2437,9 @@ void FrameView::updateLifecyclePhasesInternal(LifeCycleUpdateOption phases, cons
 
             updateCompositedSelectionIfNeeded();
 
+            if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+                calculatePaintProperties();
+
             if (RuntimeEnabledFeatures::slimmingPaintSynchronizedPaintingEnabled()) {
                 synchronizedPaint(interestRect);
                 if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
@@ -2453,6 +2456,19 @@ void FrameView::updateLifecyclePhasesInternal(LifeCycleUpdateOption phases, cons
     }
 }
 
+void FrameView::calculatePaintProperties()
+{
+    ASSERT(RuntimeEnabledFeatures::slimmingPaintV2Enabled());
+
+    // Detached frames can have no root graphics layer so skip even calculating paint properties.
+    if (!layoutView()->layer()->graphicsLayerBacking())
+        return;
+
+    lifecycle().advanceTo(DocumentLifecycle::InCalcPaintProps);
+    // TODO(pdr): Calculate the paint properties by walking the layout tree.
+    lifecycle().advanceTo(DocumentLifecycle::CalcPaintPropsClean);
+}
+
 void FrameView::synchronizedPaint(const LayoutRect& interestRect)
 {
     ASSERT(RuntimeEnabledFeatures::slimmingPaintSynchronizedPaintingEnabled());