Add VectorIconButton functionality to ImageButton.

ui/views/controls/button/image_button.cc

Index: ui/views/controls/button/image_button.cc
diff --git a/ui/views/controls/button/image_button.cc b/ui/views/controls/button/image_button.cc
index fd2151e2a1aab73c6ad529ec5a909ffd9ea309ab..2eb38bda8cc715668720fa46dfc0f2c68c5d2224 100644
--- a/ui/views/controls/button/image_button.cc
+++ b/ui/views/controls/button/image_button.cc
@@ -12,6 +12,7 @@
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image_skia_operations.h"
 #include "ui/gfx/scoped_canvas.h"
+#include "ui/views/border.h"
 #include "ui/views/painter.h"
 #include "ui/views/widget/widget.h"
 
@@ -95,6 +96,13 @@ void ImageButton::SetMinimumImageSize(const gfx::Size& size) {
   PreferredSizeChanged();
 }
 
+void ImageButton::SetPadding(const gfx::Insets& padding) {
+  if (padding.IsEmpty())
+    SetBorder(NullBorder());
+  else
+    SetBorder(CreateEmptyBorder(padding));
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // ImageButton, View overrides: