Use a background for the main search box in 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"
 #include "base/files/file_path.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_util.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_folder_item.h"
 #include "ui/app_list/app_list_item.h"
 #include "ui/app_list/app_list_model.h"
 #include "ui/app_list/app_list_switches.h"
 #include "ui/app_list/app_list_view_delegate.h"
 #include "ui/app_list/pagination_model.h"
 #include "ui/app_list/search_box_model.h"
 #include "ui/app_list/views/app_list_folder_view.h"
 #include "ui/app_list/views/app_list_item_view.h"
 #include "ui/app_list/views/apps_container_view.h"
 #include "ui/app_list/views/apps_grid_view.h"
 #include "ui/app_list/views/contents_switcher_view.h"
 #include "ui/app_list/views/contents_view.h"
 #include "ui/app_list/views/search_box_view.h"
+#include "ui/views/border.h"
 #include "ui/views/controls/textfield/textfield.h"
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/layout/fill_layout.h"
 #include "ui/views/widget/widget.h"
 
 namespace app_list {
 
 namespace {
 
 // Inner padding space in pixels of bubble contents.
 const int kInnerPadding = 1;
 
 // The maximum allowed time to wait for icon loading in milliseconds.
 const int kMaxIconLoadingWaitTimeInMs = 50;
 
+// The padding around the search box in the experimental app list.
+const int kExperimentalSearchBoxViewPadding = 24;

[Matt Giuca, 2014/08/25 05:15:25]

Don't use "Experimental" here. It won't be experimental forever so I think we
can start using vanilla language unless there is a conflict.

[calamity, 2014/08/26 01:16:30]

Done.

+const int kExperimentalSearchBoxViewPaddingBottom = 12;
+
 // A view that holds another view and takes its preferred size. This is used for
 // wrapping the search box view so it still gets laid out while hidden. This is
 // a separate class so it can notify the main view on search box visibility
 // change.
 class SearchBoxContainerView : public views::View {
  public:
   SearchBoxContainerView(AppListMainView* host, SearchBoxView* search_box)
       : host_(host), search_box_(search_box) {
     SetLayoutManager(new views::FillLayout());
     AddChildView(search_box);
@@ skipping 63 matching lines @@
       search_box_view_(NULL),
       contents_view_(NULL),
       contents_switcher_view_(NULL),
       weak_ptr_factory_(this) {
   SetLayoutManager(new views::BoxLayout(views::BoxLayout::kVertical,
                                         kInnerPadding,
                                         kInnerPadding,
                                         kInnerPadding));
 
   search_box_view_ = new SearchBoxView(this, delegate);
-  AddChildView(new SearchBoxContainerView(this, search_box_view_));
+  views::View* container = new SearchBoxContainerView(this, search_box_view_);
+  container->SetBorder(
+      views::Border::CreateEmptyBorder(kExperimentalSearchBoxViewPadding,
+                                       kExperimentalSearchBoxViewPadding,
+                                       kExperimentalSearchBoxViewPaddingBottom,
+                                       kExperimentalSearchBoxViewPadding));
+  AddChildView(container);
   AddContentsViews();
 
   // Switch the apps grid view to the specified page.
   app_list::PaginationModel* pagination_model = GetAppsPaginationModel();
   if (pagination_model->is_valid_page(initial_apps_page))
     pagination_model->SelectPage(initial_apps_page, false);
 
   // Starts icon loading early.
   PreloadIcons(parent);
 }
@@ skipping 194 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