Add GetMinimumSize() for Borders, and make LabelButton auto-size to at least as

ui/views/shadow_border.cc

Index: ui/views/shadow_border.cc
===================================================================
--- ui/views/shadow_border.cc	(revision 236640)
+++ ui/views/shadow_border.cc	(working copy)
@@ -34,6 +34,8 @@
   paint.setColor(SK_ColorTRANSPARENT);
   paint.setStrokeJoin(SkPaint::kRound_Join);
   gfx::Rect bounds(view.size());
+  // TODO(pkasting): This isn't right if one of the offsets is larger than
+  // (blur_ / 2).
   bounds.Inset(gfx::Insets(blur_ / 2, blur_ / 2, blur_ / 2, blur_ / 2));
   canvas->DrawRect(bounds, paint);
 }
@@ -45,4 +47,8 @@
                      blur_ / 2 + horizontal_offset_);
 }
 
+gfx::Size ShadowBorder::GetMinimumSize() const {
+  return gfx::Size(blur_, blur_);
+}
+
 }  // namespace views