Make the extra padding around VectorIconButtons configurable.

ui/views/controls/button/vector_icon_button.cc

Index: ui/views/controls/button/vector_icon_button.cc
diff --git a/ui/views/controls/button/vector_icon_button.cc b/ui/views/controls/button/vector_icon_button.cc
index c3e1ba2b684548a673a7d3b1f16b6af532f51a8e..79c62ff5d9afd8d01d444cedf42cb36e1875bc3b 100644
--- a/ui/views/controls/button/vector_icon_button.cc
+++ b/ui/views/controls/button/vector_icon_button.cc
@@ -8,19 +8,15 @@
 #include "ui/gfx/color_utils.h"
 #include "ui/gfx/paint_vector_icon.h"
 #include "ui/gfx/vector_icons_public.h"
+#include "ui/views/animation/ink_drop_highlight.h"
+#include "ui/views/animation/ink_drop_ripple.h"
 #include "ui/views/border.h"
 #include "ui/views/controls/button/vector_icon_button_delegate.h"
 #include "ui/views/painter.h"
+#include "ui/views/views_delegate.h"
 
 namespace views {
 
-namespace {
-
-// Extra space around the buttons to increase their event target size.
-const int kButtonExtraTouchSize = 4;
-
-}  // namespace
-
 VectorIconButton::VectorIconButton(VectorIconButtonDelegate* delegate)
     : ImageButton(delegate),
       delegate_(delegate),
@@ -55,9 +51,20 @@ void VectorIconButton::OnNativeThemeChanged(const ui::NativeTheme* theme) {
   UpdateImagesAndColors();
 }
 
+std::unique_ptr<InkDropRipple> VectorIconButton::CreateInkDropRipple() const {
+  return CreateDefaultInkDropRipple(GetLocalBounds().CenterPoint(), size());
+}
+
+std::unique_ptr<InkDropHighlight> VectorIconButton::CreateInkDropHighlight()
+    const {
+  return CreateDefaultInkDropHighlight(
+      gfx::RectF(GetLocalBounds()).CenterPoint(), size());
+}
+
 void VectorIconButton::OnSetIcon() {
-  if (!border())
-    SetBorder(CreateEmptyBorder(gfx::Insets(kButtonExtraTouchSize)));
+  const gfx::Insets insets = ViewsDelegate::GetInstance()->GetButtonPadding();

[sky, 2017/02/01 16:57:28]

Is the plan to use GetButtonPadding in all buttons? If not, I think the name
should be more specific. Perhaps VectorIconButtonPadding.

[Peter Kasting, 2017/02/01 19:48:45]

I think that concern is fair.  I hate being so specific with a constant that
lives in such a global place, but the real issue there is the constant needing
to live there to begin with.

If I keep this constant, I will change the name.  It can always be renamed later
if we generalize.

+  if (!border() && !insets.IsEmpty())
+    SetBorder(CreateEmptyBorder(insets));
 
   UpdateImagesAndColors();
 }