views: Make view::Views::GetPreferredSize() const.

ui/message_center/views/bounded_label.cc

Index: ui/message_center/views/bounded_label.cc
diff --git a/ui/message_center/views/bounded_label.cc b/ui/message_center/views/bounded_label.cc
index 1b2412aa1b33d5f3a9b790ea6697f28a54514fe3..8c19c9d93f07c1124d76c414a3b2193b68449b86 100644
--- a/ui/message_center/views/bounded_label.cc
+++ b/ui/message_center/views/bounded_label.cc
@@ -326,11 +326,11 @@ int BoundedLabel::GetBaseline() const {
   return label_->GetBaseline();
 }
 
-gfx::Size BoundedLabel::GetPreferredSize() {
+gfx::Size BoundedLabel::GetPreferredSize() const {
   return visible() ? label_->GetSizeForWidthAndLines(-1, -1) : gfx::Size();
 }
 
-int BoundedLabel::GetHeightForWidth(int width) {
+int BoundedLabel::GetHeightForWidth(int width) const {
   return visible() ?
          label_->GetSizeForWidthAndLines(width, line_limit_).height() : 0;
 }