[win] Initialize the app list menu lazily, and allow invalidation.

ui/app_list/views/search_box_view.cc

Index: ui/app_list/views/search_box_view.cc
diff --git a/ui/app_list/views/search_box_view.cc b/ui/app_list/views/search_box_view.cc
index 1187ecf6ade5434dd19545d66ef538ebb27fdec3..73a04a60ac294bef55569be699f5c86ce75d871f 100644
--- a/ui/app_list/views/search_box_view.cc
+++ b/ui/app_list/views/search_box_view.cc
@@ -9,6 +9,7 @@
 #include "grit/ui_resources.h"
 #include "ui/app_list/search_box_model.h"
 #include "ui/app_list/search_box_view_delegate.h"
+#include "ui/app_list/views/app_list_menu_views.h"
 #include "ui/base/events/event.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/views/controls/button/menu_button.h"
@@ -32,8 +33,8 @@ const SkColor kHintTextColor = SkColorSetRGB(0xA0, 0xA0, 0xA0);
 SearchBoxView::SearchBoxView(SearchBoxViewDelegate* delegate,
                              AppListViewDelegate* view_delegate)
     : delegate_(delegate),
+      view_delegate_(view_delegate),
       model_(NULL),
-      menu_(view_delegate),
       icon_view_(new views::ImageView),
       search_box_(new views::Textfield),
       contents_view_(NULL) {
@@ -90,6 +91,10 @@ void SearchBoxView::ClearSearch() {
   NotifyQueryChanged();
 }
 
+void SearchBoxView::InvalidateMenu() {
+  menu_.reset();
+}
+
 gfx::Size SearchBoxView::GetPreferredSize() {
   return gfx::Size(kPreferredWidth, kPreferredHeight);
 }
@@ -159,8 +164,11 @@ bool SearchBoxView::HandleKeyEvent(views::Textfield* sender,
 }
 
 void SearchBoxView::OnMenuButtonClicked(View* source, const gfx::Point& point) {
-  menu_.RunMenuAt(menu_button_,
-                  menu_button_->GetBoundsInScreen().bottom_right());
+  if (!menu_)
+    menu_.reset(new AppListMenuViews(view_delegate_));
+
+  menu_->RunMenuAt(menu_button_,
+                   menu_button_->GetBoundsInScreen().bottom_right());
 }
 
 void SearchBoxView::IconChanged() {