[css-grid] Cache definite height detection

third_party/WebKit/Source/core/layout/LayoutGrid.h

Index: third_party/WebKit/Source/core/layout/LayoutGrid.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutGrid.h b/third_party/WebKit/Source/core/layout/LayoutGrid.h
index 2847078d6ca00f3b8cadac00ce3ff950d1126e8d..3e4c2a66480892282de83d22d0a9c18d7c05728d 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.h
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.h
@@ -220,6 +220,12 @@ private:
     bool isOrthogonalChild(const LayoutBox&) const;
     GridTrackSizingDirection flowAwareDirectionForChild(const LayoutBox&, GridTrackSizingDirection) const;
 
+    bool hasDefiniteLogicalHeight() const

[jfernandez, 2016/09/15 07:27:11]

This method has the same name than the one defined in LayoutBox class, but we
are not override it; we don't do it because both methods are of a different
nature, indeed. I'd rather use a different name for this getter method, to avoid
confusions and the need of specifying the class on invocation.

[svillar, 2016/09/15 08:02:22]

Agree, do not use the same name, someone could be tempted to add an override and
then we'd be ... you know :)

Also let's not add multiline implementations in the class definition, they make
it much more difficult to understand.

[Manuel Rego, 2016/09/15 08:56:04]

True, I'll change the name to cachedHasDefiniteLogicalHeight().
Done.

+    {
+        SECURITY_DCHECK(m_hasDefiniteLogicalHeight);
+        return m_hasDefiniteLogicalHeight.value();

[svillar, 2016/09/15 08:02:22]

For caching like methods I think it's preferred some other form

if (!m_hasDefiniteLogicalHeight)
   m_hasDefiniteLogicalHeight = hasDefiniteLogicalHeight();
return m_hasDefiniteLogicalHeight.value();

[svillar, 2016/09/15 08:16:00]

Beh, forget about this. We need to call it on every layout so what I was
suggesting is wrong.

+    }
+
     typedef Vector<Vector<GridCell>> GridRepresentation;
     GridRepresentation m_grid;
     bool m_gridIsDirty;
@@ -245,6 +251,8 @@ private:
 
     std::unique_ptr<OrderedTrackIndexSet> m_autoRepeatEmptyColumns { nullptr };
     std::unique_ptr<OrderedTrackIndexSet> m_autoRepeatEmptyRows { nullptr };
+
+    Optional<bool> m_hasDefiniteLogicalHeight;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutGrid, isLayoutGrid());