Correctly handle tab navigation in the app list.

ui/app_list/views/app_list_view.cc

 // Copyright (c) 2012 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_view.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
@@ skipping 65 matching lines @@
           ::switches::kDisableDwmComposition)) {
     return false;
   }
 #elif defined(OS_LINUX) && !defined(OS_CHROMEOS)
   // Shadows are not supported on (non-ChromeOS) Linux.
   return false;
 #endif
   return true;
 }
 
+// This view forwards the focus to the search box widget by providing it as a
+// FocusTraversable when a focus search is provided.
+class SearchBoxFocusHost : public views::View {
+ public:
+  explicit SearchBoxFocusHost(views::Widget* search_box_widget)
+      : search_box_widget_(search_box_widget) {}
+
+  ~SearchBoxFocusHost() override {}
+
+  views::FocusTraversable* GetFocusTraversable() override {
+    return search_box_widget_;
+  }
+
+ private:
+  views::Widget* search_box_widget_;
+
+  DISALLOW_COPY_AND_ASSIGN(SearchBoxFocusHost);
+};
+
 // The view for the App List overlay, which appears as a white rounded
 // rectangle with the given radius.
 class AppListOverlayView : public views::View {
  public:
   explicit AppListOverlayView(int corner_radius)
       : corner_radius_(corner_radius) {
     SetPaintToLayer(true);
     SetVisible(false);
     layer()->SetOpacity(0.0f);
   }
@@ skipping 79 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(HideViewAnimationObserver);
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 // AppListView:
 
 AppListView::AppListView(AppListViewDelegate* delegate)
     : delegate_(delegate),
       app_list_main_view_(nullptr),
       speech_view_(nullptr),
+      search_box_focus_host_(nullptr),
       search_box_widget_(nullptr),
       search_box_view_(nullptr),
       overlay_view_(nullptr),
       animation_observer_(new HideViewAnimationObserver()) {
   CHECK(delegate);
 
   delegate_->AddObserver(this);
   delegate_->GetSpeechUI()->AddObserver(this);
 }
 
@@ skipping 261 matching lines @@
   search_box_widget_params.opacity =
       views::Widget::InitParams::TRANSLUCENT_WINDOW;
 
   // Create a widget for the SearchBoxView to live in. This allows the
   // SearchBoxView to be on top of the custom launcher page's WebContents
   // (otherwise the search box events will be captured by the WebContents).
   search_box_widget_ = new views::Widget;
   search_box_widget_->Init(search_box_widget_params);
   search_box_widget_->SetContentsView(search_box_view_);
 
+  // The search box will not naturally receive focus by itself (because it is in
+  // a separate widget). Create this SearchBoxFocusHost in the main widget to
+  // forward the focus search into to the search box.
+  search_box_focus_host_ = new SearchBoxFocusHost(search_box_widget_);
+  AddChildView(search_box_focus_host_);
+  search_box_widget_->SetFocusTraversableParentView(search_box_focus_host_);
+  search_box_widget_->SetFocusTraversableParent(
+      GetWidget()->GetFocusTraversable());
+
 #if defined(USE_AURA)
   // Mouse events on the search box shadow should not be captured.
   aura::Window* window = search_box_widget_->GetNativeWindow();
   window->SetEventTargeter(scoped_ptr<ui::EventTargeter>(
       new SearchBoxWindowTargeter(search_box_view_)));
 #endif
 
   app_list_main_view_->contents_view()->Layout();
 }
 
@@ skipping 294 matching lines @@
 
   if (will_appear) {
     speech_view_->SetVisible(true);
   } else {
     app_list_main_view_->SetVisible(true);
     search_box_view_->search_box()->RequestFocus();
   }
 }
 
 }  // namespace app_list