Fix MenuModelAdapter clang build

views/controls/menu/menu_model_adapter_unittest.cc

Index: views/controls/menu/menu_model_adapter_unittest.cc
diff --git a/views/controls/menu/menu_model_adapter_unittest.cc b/views/controls/menu/menu_model_adapter_unittest.cc
index 060d01ee7b0b5487b87028ea16d8664072470dd4..dba68c80f1bed0e481a5e1394caa42cb6b89830e 100644
--- a/views/controls/menu/menu_model_adapter_unittest.cc
+++ b/views/controls/menu/menu_model_adapter_unittest.cc
@@ -26,6 +26,9 @@ class MenuModelBase : public ui::MenuModel {
                                        last_activation_(-1) {
   }
 
+  virtual ~MenuModelBase() {
+  }
+
   // ui::MenuModel implementation:
 
   virtual bool HasIcons() const OVERRIDE {
@@ -157,6 +160,9 @@ class SubmenuModel : public MenuModelBase {
     items_.push_back(Item(TYPE_COMMAND, "submenu item 1", NULL));
   }
 
+  virtual ~SubmenuModel() {
+  }
+
  private:
   DISALLOW_COPY_AND_ASSIGN(SubmenuModel);
 };
@@ -173,6 +179,9 @@ class RootModel : public MenuModelBase {
     items_.push_back(Item(TYPE_RADIO, "radio 4", NULL));
   }
 
+  virtual ~RootModel() {
+  }
+
  private:
   scoped_ptr<MenuModel> submenu_model_;