Make CaretBase a DisplayItemClient.

third_party/WebKit/Source/core/layout/LayoutBlock.cpp

Index: third_party/WebKit/Source/core/layout/LayoutBlock.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
index 754ba3498df89678cbba151237cb7186ba27e57c..9b9e41c7a30406bdfec182440e7f44e93e166b1d 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.cpp
@@ -226,6 +226,15 @@ void LayoutBlock::styleDidChange(StyleDifference diff, const ComputedStyle* oldS
     m_heightAvailableToChildrenChanged |= oldStyle && diff.needsFullLayout() && needsLayout() && borderOrPaddingLogicalDimensionChanged(*oldStyle, newStyle, LogicalHeight);
 }
 
+void LayoutBlock::invalidateCaret() const
+{
+    if (hasCaret()) {
+        ObjectPaintInvalidator(*this).slowSetPaintingLayerNeedsRepaint();
+        frame()->selection().setCaretRectNeedsUpdate();
+        frame()->selection().invalidateCaretRect(true);
+    }
+}
+
 void LayoutBlock::updateFromStyle()
 {
     LayoutBox::updateFromStyle();
@@ -922,6 +931,14 @@ void LayoutBlock::removePositionedObject(LayoutBox* o)
     }
 }
 
+PaintInvalidationReason LayoutBlock::invalidatePaintIfNeeded(const PaintInvalidationState& paintInvalidationState)
+{
+    PaintInvalidationReason reason = LayoutBox::invalidatePaintIfNeeded(paintInvalidationState);
+    if (reason != PaintInvalidationNone)
+        invalidateCaret();
+    return reason;
+}
+
 void LayoutBlock::removePositionedObjects(LayoutBlock* o, ContainingBlockState containingBlockState)
 {
     TrackedLayoutBoxListHashSet* positionedDescendants = positionedObjects();