Let FrameSelection::localCaretRect on a text input field avoid synchronous layout.

Source/core/editing/Caret.h

Index: Source/core/editing/Caret.h
diff --git a/Source/core/editing/Caret.h b/Source/core/editing/Caret.h
index 34febde4c89cd0703561c6358c5baa17fb418003..8caa9b2ac39533357119386be9362447523e8a08 100644
--- a/Source/core/editing/Caret.h
+++ b/Source/core/editing/Caret.h
@@ -35,6 +35,7 @@ namespace blink {
 
 class LocalFrame;
 class GraphicsContext;
+class PositionWithAffinity;
 class RenderBlock;
 class RenderView;
 
@@ -47,6 +48,7 @@ protected:
 
     void invalidateCaretRect(Node*, bool caretRectChanged = false);
     void clearCaretRect();
+    bool updateCaretRect(Document*, const PositionWithAffinity& caretPosition);
     bool updateCaretRect(Document*, const VisiblePosition& caretPosition);
     IntRect absoluteBoundsForLocalRect(Node*, const LayoutRect&) const;
     bool shouldRepaintCaret(const RenderView*, bool isContentEditable) const;