[Autofill] Handle the Tab Key in the new UI

chrome/browser/ui/autofill/autofill_popup_controller_impl.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 "chrome/browser/ui/autofill/autofill_popup_controller_impl.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/logging.h"
@@ skipping 195 matching lines @@
       return true;
     case ui::VKEY_NEXT:  // Page down.
       SetSelectedLine(names().size() - 1);
       return true;
     case ui::VKEY_ESCAPE:
       Hide();
       return true;
     case ui::VKEY_DELETE:
       return (event.modifiers & content::NativeWebKeyboardEvent::ShiftKey) &&
              RemoveSelectedLine();
+    case ui::VKEY_TAB:
+      // A tab press should cause the highlighted line to be selected, but still
+      // return false so the tab key press propagates and changes the cursor
+      // location.
+      AcceptSelectedLine();
+      return false;
     case ui::VKEY_RETURN:
       return AcceptSelectedLine();
     default:
       return false;
   }
 }
 
 void AutofillPopupControllerImpl::UpdateBoundsAndRedrawPopup() {
 #if !defined(OS_ANDROID)
   // TODO(csharp): Since UpdatePopupBounds can change the position of the popup,
@@ skipping 394 matching lines @@
     // The popup can appear below the field.
     return std::make_pair(bottom_growth_start, popup_required_height);
   } else {
     // The popup must appear above the field.
     return std::make_pair(top_growth_end - popup_required_height,
                           popup_required_height);
   }
 }
 
 }  // namespace autofill