Blink caret only if selection has focus.

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

 /*
  * Copyright (C) 2004, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 73 matching lines @@
 
   // For unit tests.
   const DisplayItemClient& CaretDisplayItemClientForTesting() const;
   const LayoutBlock* CaretLayoutBlockForTesting() const;
   bool ShouldPaintCaretForTesting() const { return should_paint_caret_; }
   void RecreateCaretBlinkTimerForTesting(RefPtr<WebTaskRunner>);
 
   DECLARE_TRACE();
 
  private:
+  friend class FrameCaretTest;
   friend class FrameSelectionTest;
 
   const PositionWithAffinity CaretPosition() const;
 
   bool ShouldBlinkCaret() const;
   void CaretBlinkTimerFired(TimerBase*);
   bool CaretPositionIsValidForDocument(const Document&) const;
   void UpdateAppearance();
 
   const Member<const SelectionEditor> selection_editor_;
   const Member<LocalFrame> frame_;
   const std::unique_ptr<CaretDisplayItemClient> display_item_client_;
   CaretVisibility caret_visibility_;
   // TODO(https://crbug.com/668758): Consider using BeginFrame update for this.
   std::unique_ptr<TaskRunnerTimer<FrameCaret>> caret_blink_timer_;
   bool should_paint_caret_ : 1;
   bool is_caret_blinking_suspended_ : 1;
   bool should_show_block_cursor_ : 1;
 
   DISALLOW_COPY_AND_ASSIGN(FrameCaret);
 };
 
 }  // namespace blink
 
 #endif  // FrameCaret_h