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

ui/views/controls/button/label_button_border.cc

Index: ui/views/controls/button/label_button_border.cc
===================================================================
--- ui/views/controls/button/label_button_border.cc	(revision 236640)
+++ ui/views/controls/button/label_button_border.cc	(working copy)
@@ -158,6 +158,17 @@
   return insets_;
 }
 
+gfx::Size LabelButtonBorder::GetMinimumSize() const {
+  gfx::Size minimum_size;
+  for (int i = 0; i < 2; ++i) {
+    for (int j = 0; j < Button::STATE_COUNT; ++j) {
+      if (painters_[i][j])
+        minimum_size.SetToMax(painters_[i][j]->GetMinimumSize());
+    }
+  }
+  return minimum_size;
+}
+
 Painter* LabelButtonBorder::GetPainter(bool focused,
                                        Button::ButtonState state) {
   return painters_[focused ? 1 : 0][state].get();