Mark when we may have been invalidated to early out on repaintTreeAfterLayout.

Source/core/rendering/RenderObject.h

Index: Source/core/rendering/RenderObject.h
diff --git a/Source/core/rendering/RenderObject.h b/Source/core/rendering/RenderObject.h
index bd27cc85d31a91811bfb79949d3c105b1ab14e10..eeb63c9d7d65fd90b3da2dbac905066ef8f1c25f 100644
--- a/Source/core/rendering/RenderObject.h
+++ b/Source/core/rendering/RenderObject.h
@@ -995,6 +995,7 @@ public:
 
     bool shouldDoFullRepaintAfterLayout() const { return m_bitfields.shouldDoFullRepaintAfterLayout(); }
     void setShouldDoFullRepaintAfterLayout(bool b) { m_bitfields.setShouldDoFullRepaintAfterLayout(b); }
+

[leviw_travelin_and_unemployed, 2014/05/05 18:52:32]

Nit: empty line.

[Julien - ping for review, 2014/05/05 19:02:35]

Unneeded space.

[dsinclair, 2014/05/05 19:38:26]

Done.

[dsinclair, 2014/05/05 19:38:26]

Done.

     bool shouldRepaintOverflow() const { return m_bitfields.shouldRepaintOverflow(); }
 
     bool shouldDoFullRepaintIfSelfPaintingLayer() const { return m_bitfields.shouldDoFullRepaintIfSelfPaintingLayer(); }
@@ -1010,6 +1011,21 @@ public:
     bool layoutDidGetCalled() { return m_bitfields.layoutDidGetCalled(); }
     void setLayoutDidGetCalled(bool b) { m_bitfields.setLayoutDidGetCalled(b); }
 
+    bool mayNeedInvalidation() { return m_bitfields.mayNeedInvalidation(); }
+    void setMayNeedInvalidation(bool b)
+    {
+        m_bitfields.setMayNeedInvalidation(b);
+
+        // Make sure our parent is marked as needing invalidation.

[Julien - ping for review, 2014/05/05 19:02:35]

Interesting, the needs layout logic walks up the tree, marking as it goes, until
it find an ancestor needing layout.

Here we only need to mark the parent, which means that we don't forget renderers
deep into the tree. Either that or we don't have coverage for it.

[dsinclair, 2014/05/05 19:38:26]

Not sure what I need to do for this? We mark our parent, and the parent may mark
it's ancestor. But, as soon as we hit an ancestor that is marked we know we're
done.

+        if (b && parent() && !parent()->mayNeedInvalidation())
+            parent()->setMayNeedInvalidation(b);
+    }
+
+    bool shouldCheckForInvalidations()

[Julien - ping for review, 2014/05/05 19:02:35]

I may be better to use shouldCheckForInvalidationAfterLayout() as we still have
the old non-repaint-after-layout code.

[dsinclair, 2014/05/05 19:38:26]

Done.

+    {
+        return layoutDidGetCalled() || mayNeedInvalidation();
+    }
+
     bool shouldDisableLayoutState() const { return hasColumns() || hasTransform() || hasReflection() || style()->isFlippedBlocksWritingMode(); }
 
     void setNeedsOverflowRecalcAfterStyleChange();
@@ -1125,6 +1141,7 @@ private:
             , m_shouldDoFullRepaintAfterLayout(false)
             , m_shouldRepaintOverflow(false)
             , m_shouldDoFullRepaintIfSelfPaintingLayer(false)
+            , m_mayNeedInvalidation(false)

[Julien - ping for review, 2014/05/05 19:02:35]

I think we should have a FIXME to remove this boolean with either a meta bug
(preferred) or pointing at the issues blocking that now (we want an actionable
FIXME)

[dsinclair, 2014/05/05 19:38:26]

Done.

             , m_onlyNeededPositionedMovementLayout(false)
             , m_needsPositionedMovementLayout(false)
             , m_normalChildNeedsLayout(false)
@@ -1159,11 +1176,12 @@ private:
         {
         }
 
-        // 32 bits have been used in the first word, and 5 in the second.
+        // 32 bits have been used in the first word, and 6 in the second.
         ADD_BOOLEAN_BITFIELD(selfNeedsLayout, SelfNeedsLayout);
         ADD_BOOLEAN_BITFIELD(shouldDoFullRepaintAfterLayout, ShouldDoFullRepaintAfterLayout);
         ADD_BOOLEAN_BITFIELD(shouldRepaintOverflow, ShouldRepaintOverflow);
         ADD_BOOLEAN_BITFIELD(shouldDoFullRepaintIfSelfPaintingLayer, ShouldDoFullRepaintIfSelfPaintingLayer);
+        ADD_BOOLEAN_BITFIELD(mayNeedInvalidation, MayNeedInvalidation);
         ADD_BOOLEAN_BITFIELD(onlyNeededPositionedMovementLayout, OnlyNeededPositionedMovementLayout);
         ADD_BOOLEAN_BITFIELD(needsPositionedMovementLayout, NeedsPositionedMovementLayout);
         ADD_BOOLEAN_BITFIELD(normalChildNeedsLayout, NormalChildNeedsLayout);