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

ui/views/controls/styled_label.cc

Index: ui/views/controls/styled_label.cc
diff --git a/ui/views/controls/styled_label.cc b/ui/views/controls/styled_label.cc
index 24d9862c87ccc30b3ced727b11fafe47e687a783..6c76fee18d5dc3fe47e7884913313e5366964776 100644
--- a/ui/views/controls/styled_label.cc
+++ b/ui/views/controls/styled_label.cc
@@ -157,9 +157,18 @@ gfx::Insets StyledLabel::GetInsets() const {
   return insets;
 }
 
-int StyledLabel::GetHeightForWidth(int w) {
-  if (w != calculated_size_.width())
-    calculated_size_ = CalculateAndDoLayout(w, true);
+int StyledLabel::GetHeightForWidth(int w) const {
+  if (w != calculated_size_.width()) {
+    // TODO(erg): Munge the const-ness of the style label. CalculateAndDoLayout
+    // doesn't actually make any changes to member variables when |dry_run| is
+    // set to true. In general, the mutating and non-mutating parts shouldn't
+    // be in the same codepath.
+    //
+    // I only feel OK about this quick hack since this code is going away

[sky, 2014/05/13 16:13:57]

Why is this code going away?

[Elliot Glaysher, 2014/05/14 00:48:58]

I actually got the wrong impression from msw@. This code has no plans to go
away.

I still don't like it, but I guess a const_cast<> here isn't the end of the
world.

+    // anyway?
+    calculated_size_ =
+        const_cast<StyledLabel*>(this)->CalculateAndDoLayout(w, true);
+  }
   return calculated_size_.height();
 }