Prevent Shift+Tab from locking up the browser when in the app list.

ui/app_list/views/search_box_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/search_box_view.h"
 
 #include <algorithm>
 
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_model.h"
@@ skipping 203 matching lines @@
   view_delegate_->AutoLaunchCanceled();
   NotifyQueryChanged();
 }
 
 bool SearchBoxView::HandleKeyEvent(views::Textfield* sender,
                                    const ui::KeyEvent& key_event) {
   bool handled = false;
   if (contents_view_ && contents_view_->visible())
     handled = contents_view_->OnKeyPressed(key_event);
 
+  // Prevent Shift+Tab from locking up the whole chrome browser process.
+  // Explicitly capturing the Shift+Tab event here compensates for a focus
+  // search issue. We get away with this because there are no other focus
+  // targets. See http://crbug.com/438425 for details.
+  if (key_event.key_code() == ui::VKEY_TAB && key_event.IsShiftDown())
+    handled = true;
+
   return handled;
 }
 
 void SearchBoxView::ButtonPressed(views::Button* sender,
                                   const ui::Event& event) {
   if (back_button_ && sender == back_button_)
     delegate_->BackButtonPressed();
   else if (speech_button_ && sender == speech_button_)
     view_delegate_->ToggleSpeechRecognition();
   else
@@ skipping 57 matching lines @@
   NotifyQueryChanged();
 }
 
 void SearchBoxView::OnSpeechRecognitionStateChanged(
     SpeechRecognitionState new_state) {
   SpeechRecognitionButtonPropChanged();
   SchedulePaint();
 }
 
 }  // namespace app_list