Auto-size the views version of the options dialog.

views/widget/widget_gtk.cc

Index: views/widget/widget_gtk.cc
diff --git a/views/widget/widget_gtk.cc b/views/widget/widget_gtk.cc
index 1e73e38e678fa0f5b123185ccc4b1fd627983ac8..c9144d7729008883f1bacccbf7ab1ba815b52eeb 100644
--- a/views/widget/widget_gtk.cc
+++ b/views/widget/widget_gtk.cc
@@ -500,6 +500,8 @@ void WidgetGtk::Init(GtkWidget* parent,
                         GDK_KEY_RELEASE_MASK);
   SetRootViewForWidget(widget_, root_view_.get());
 
+  g_signal_connect_after(G_OBJECT(window_contents_), "size_request",
+                         G_CALLBACK(&OnSizeRequestThunk), this);
   g_signal_connect_after(G_OBJECT(window_contents_), "size_allocate",
                          G_CALLBACK(&OnSizeAllocateThunk), this);
   gtk_widget_set_app_paintable(window_contents_, true);
@@ -883,6 +885,18 @@ int WidgetGtk::GetFlagsForEventButton(const GdkEventButton& event) {
   return flags;
 }
 
+void WidgetGtk::OnSizeRequest(GtkWidget* widget, GtkRequisition* requisition) {
+  // Do only return the preferred size for child windows. GtkWindow interprets
+  // the requisition as a minimum size for top level windows, returning a
+  // preferred size for these would prevents us from setting smaller window
+  // sizes.
+  if (type_ == TYPE_CHILD) {
+    gfx::Size size(root_view_->GetPreferredSize());
+    requisition->width = size.width();
+    requisition->height = size.height();
+  }
+}
+
 void WidgetGtk::OnSizeAllocate(GtkWidget* widget, GtkAllocation* allocation) {
   // See comment next to size_ as to why we do this. Also note, it's tempting
   // to put this in the static method so subclasses don't need to worry about