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

ui/views/border.h

Index: ui/views/border.h
diff --git a/ui/views/border.h b/ui/views/border.h
index d30cc7ca0b00e2882b2b5288d9b058a98fa3858d..f0e58e9311ee1a6d5bb82dd469cdaad5a596b71c 100644
--- a/ui/views/border.h
+++ b/ui/views/border.h
@@ -79,6 +79,10 @@ class VIEWS_EXPORT Border {
       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;