Add a skeleton Start Page to the experimental app list.

ui/app_list/views/app_list_main_view.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/app_list/views/app_list_main_view.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 147 matching lines @@
   pending_icon_loaders_.clear();
   model_ = delegate_->GetModel();
   search_box_view_->ModelChanged();
   delete contents_view_;
   contents_view_ = NULL;
   pagination_model_->SelectPage(0, false /* animate */);
   AddContentsView();
   Layout();
 }
 
+void AppListMainView::OnContentsViewShowStateChanged() {
+  search_box_view_->SetVisible(contents_view_->show_state() !=
+                               ContentsView::SHOW_START_PAGE);
+}
+
+void AppListMainView::OnStartPageSearchButtonPressed() {
+  search_box_view_->SetVisible(true);
+  search_box_view_->search_box()->SetText(base::string16());
+  search_box_view_->RequestFocus();
+}
+
 void AppListMainView::SetDragAndDropHostOfCurrentAppList(
     ApplicationDragAndDropHost* drag_and_drop_host) {
   contents_view_->SetDragAndDropHostOfCurrentAppList(drag_and_drop_host);
 }
 
 bool AppListMainView::ShouldCenterWindow() const {
   return delegate_->ShouldCenterWindow();
 }
 
 void AppListMainView::PreloadIcons(gfx::NativeView parent) {
@@ skipping 81 matching lines @@
   // Resubmit the query via a posted task so that all observers for the
   // uninstall notification are notified.
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(&AppListMainView::QueryChanged,
                  weak_ptr_factory_.GetWeakPtr(),
                  search_box_view_));
 }
 
 }  // namespace app_list