Harmony - Don't paint focus ring on unless border requests it.

ui/views/border.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_BORDER_H_
 #define UI_VIEWS_BORDER_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 61 matching lines @@
                                                         int bottom,
                                                         int right,
                                                         SkColor color);
 
   // Creates a Border from the specified Painter.
   // |insets| define size of an area allocated for a Border.
   static std::unique_ptr<Border> CreateBorderPainter(
       std::unique_ptr<Painter> painter,
       const gfx::Insets& insets);
 
+  // Returns true if a FocusRing should be used in concert with this border.
+  // Returns false by default.
+  virtual bool ShouldAddFocusRing() const;

[sky, 2016/10/06 19:34:42]

Adding functions specific to certain controls doesn't scale well. Can this be a
property of TextField? By that I mean can TextField get a specific setter as to
whether the ring should be installed?

[Evan Stade, 2016/10/06 20:14:18]

It could, but I strayed from that approach because it would be too easy to get
wrong. Not only do we have to hunt down every present textfield with a custom
border, but also in the future people have to realize the need for both calls.

Another option would be to add OnFocus and OnBlur to Border, then have
FocusableBorder be the one to install the focus ring. This would also allow us
to remove some SchedulePaint calls which are only there to refresh the border
after focus or blur.

+
   // Renders the border for the specified view.
   virtual void Paint(const View& view, gfx::Canvas* canvas) = 0;
 
   // Returns the border insets.
   virtual gfx::Insets GetInsets() const = 0;
 
   // Returns the minimum size this border requires.  Note that this may not be
   // the same as the insets.  For example, a Border may paint images to draw
   // some graphical border around a view, and this would return the minimum size
   // such that these images would not be clipped or overlapping -- but the
   // insets may be larger or smaller, depending on how the view wanted its
   // content laid out relative to these images.
   virtual gfx::Size GetMinimumSize() const = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Border);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_BORDER_H_