[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..3f62f33b4195cb8cc73bbe50a84f6f466cb0a152 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"
@@ -29,11 +30,9 @@ const SkColor kHintTextColor = SkColorSetRGB(0xA0, 0xA0, 0xA0);
 
 }  // namespace
 
-SearchBoxView::SearchBoxView(SearchBoxViewDelegate* delegate,
-                             AppListViewDelegate* view_delegate)
+SearchBoxView::SearchBoxView(SearchBoxViewDelegate* delegate)
     : delegate_(delegate),
       model_(NULL),
-      menu_(view_delegate),
       icon_view_(new views::ImageView),
       search_box_(new views::Textfield),
       contents_view_(NULL) {
@@ -90,6 +89,10 @@ void SearchBoxView::ClearSearch() {
   NotifyQueryChanged();
 }
 
+void SearchBoxView::UpdateMenu(AppListViewDelegate* view_delegate) {
+  menu_.reset(new AppListMenuViews(view_delegate));
+}
+
 gfx::Size SearchBoxView::GetPreferredSize() {
   return gfx::Size(kPreferredWidth, kPreferredHeight);
 }
@@ -159,8 +162,8 @@ bool SearchBoxView::HandleKeyEvent(views::Textfield* sender,
 }
 
 void SearchBoxView::OnMenuButtonClicked(View* source, const gfx::Point& point) {
-  menu_.RunMenuAt(menu_button_,
-                  menu_button_->GetBoundsInScreen().bottom_right());
+  menu_->RunMenuAt(menu_button_,
+                   menu_button_->GetBoundsInScreen().bottom_right());
 }
 
 void SearchBoxView::IconChanged() {