Make CaretBase a DisplayItemClient.

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

Index: third_party/WebKit/Source/core/layout/LayoutObject.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.cpp b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
index 5039f4bcc8dd294fffed8b9fe8257cdef27623d3..1832030d8690dcacfb7d1ceacffd839f35ad7e3e 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
@@ -1118,9 +1118,9 @@ IntSize LayoutObject::scrollAdjustmentForPaintInvalidation(const LayoutBoxModelO
     return IntSize();
 }
 
-void LayoutObject::invalidatePaintRectangle(const LayoutRect& dirtyRect, DisplayItemClient* displayItemClient) const
+LayoutRect LayoutObject::invalidatePaintRectangle(const LayoutRect& dirtyRect, DisplayItemClient* displayItemClient) const
 {
-    ObjectPaintInvalidator(*this).invalidatePaintRectangle(dirtyRect, displayItemClient);
+    return ObjectPaintInvalidator(*this).invalidatePaintRectangle(dirtyRect, displayItemClient);
 }
 
 void LayoutObject::invalidateTreeIfNeeded(const PaintInvalidationState& paintInvalidationState)