Fix caret paint invalidation issues

third_party/WebKit/Source/core/editing/CaretDisplayItemClient.h

Index: third_party/WebKit/Source/core/editing/CaretDisplayItemClient.h
diff --git a/third_party/WebKit/Source/core/editing/CaretDisplayItemClient.h b/third_party/WebKit/Source/core/editing/CaretDisplayItemClient.h
index 576381e0f7a23dae49da8521e18c93c24bd8a043..59bf27c32d81d944997dc859af6f4f8b577ec689 100644
--- a/third_party/WebKit/Source/core/editing/CaretDisplayItemClient.h
+++ b/third_party/WebKit/Source/core/editing/CaretDisplayItemClient.h
@@ -104,19 +104,16 @@ class CaretDisplayItemClient final : public DisplayItemClient {
   LayoutRect m_localRect;
   LayoutBlock* m_layoutBlock = nullptr;
 
-  // This is set to the previous value of m_layoutBlock during
-  // updateStyleAndLayoutIfNeeded() and can be used in invalidatePaintIfNeeded()
-  // only.
-  const LayoutBlock* m_previousLayoutBlock = nullptr;
-
   // Visual rect of the caret in m_layoutBlock. This is updated by
   // invalidatePaintIfNeeded().
   LayoutRect m_visualRect;
 
-  // This is set to the previous value of m_visualRect during
-  // updateStyleAndLayoutIfNeeded() and can be used in invalidatePaintIfNeeded()
-  // only.
-  LayoutRect m_previousVisualRect;
+  // These are set to the previous value of m_layoutBlock and m_visualRect
+  // during updateStyleAndLayoutIfNeeded() if they haven't been set since the
+  // last paint invalidation. They can only be used in invalidatePaintIfNeeded()
+  // to invalidate the caret in the previous layout block.
+  const LayoutBlock* m_previousLayoutBlock = nullptr;
+  LayoutRect m_visualRectInPreviousLayoutBlock;
 
   bool m_needsPaintInvalidation = false;
 };