Invalidate caret during paint invalidation

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

Index: third_party/WebKit/Source/core/layout/LayoutBlock.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlock.h b/third_party/WebKit/Source/core/layout/LayoutBlock.h
index d2014ceca0ec4cc5096d16ab95235954deaecd7b..12154475ec18c10caf224b424869c15ac2513a42 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlock.h
+++ b/third_party/WebKit/Source/core/layout/LayoutBlock.h
@@ -490,12 +490,60 @@ class CORE_EXPORT LayoutBlock : public LayoutBox {
   bool hasDragCaret() const;
   bool hasCaret() const { return hasCursorCaret() || hasDragCaret(); }
 
+  class MutableForPainting : public LayoutBox::MutableForPainting {
+   public:
+    void setHasPreviousCaretVisualRects(bool b) {
+      static_cast<LayoutBlock&>(m_layoutObject).m_hasPreviousCaretVisualRects =
+          b;
+    }
+
+   protected:
+    friend class LayoutBlock;
+    MutableForPainting(const LayoutBlock& layoutBlock)
+        : LayoutBox::MutableForPainting(layoutBlock) {}
+  };
+
+  MutableForPainting getMutableForPainting() const {
+    return MutableForPainting(*this);
+  }
+
+  // Called when a cursor caret or drag caret in this LayoutBlock need paint

[chrishtr, 2017/01/31 22:51:04]

Nit: "needs"

+  // invalidation, e.g. when its color or visibility changes. When a caret
+  // just changes location, use setMayNeedPaintInvalidation() instead.
+  void setCaretsNeedPaintInvalidation() {
+    if (m_caretsNeedPaintInvalidation)
+      return;
+    m_caretsNeedPaintInvalidation = true;
+    setMayNeedPaintInvalidation();
+  }
+  bool caretsNeedPaintInvalidation() const {
+    return m_caretsNeedPaintInvalidation;
+  }
+
+  bool hasPreviousCaretVisualRects() const {
+    return m_hasPreviousCaretVisualRects;
+  }
+
  protected:
   PaintInvalidationReason invalidatePaintIfNeeded(
       const PaintInvalidationState&) override;
   PaintInvalidationReason invalidatePaintIfNeeded(
       const PaintInvalidatorContext&) const override;
 
+  void clearPaintInvalidationFlags() override {
+    LayoutBox::clearPaintInvalidationFlags();
+    m_caretsNeedPaintInvalidation = false;
+  }
+
+  void clearPreviousVisualRects() override;
+
+#if DCHECK_IS_ON()
+  bool paintInvalidationStateIsDirty() const override {
+    return LayoutBox::paintInvalidationStateIsDirty() ||
+           m_caretsNeedPaintInvalidation;
+  }
+#endif
+
  private:
   LayoutRect localCaretRect(InlineBox*,
                             int caretOffset,
@@ -552,6 +600,12 @@ class CORE_EXPORT LayoutBlock : public LayoutBox {
   // to, for all we know.
   unsigned m_paginationStateChanged : 1;
 
+  // Indicates if we have saved previous cursor and/or drag caret visual rects
+  // for the LayoutBlock in BlockPaintInvalidator.
+  unsigned m_hasPreviousCaretVisualRects : 1;
+
+  unsigned m_caretsNeedPaintInvalidation : 1;
+
   // FIXME: This is temporary as we move code that accesses block flow
   // member variables out of LayoutBlock and into LayoutBlockFlow.
   friend class LayoutBlockFlow;