Enabled pressing TAB to cycle through the Omnibox results.

chrome/browser/ui/views/omnibox/omnibox_view_win.cc

Index: chrome/browser/ui/views/omnibox/omnibox_view_win.cc
===================================================================
--- chrome/browser/ui/views/omnibox/omnibox_view_win.cc	(revision 116848)
+++ chrome/browser/ui/views/omnibox/omnibox_view_win.cc	(working copy)
@@ -2063,17 +2063,17 @@
     }
 
     case VK_TAB: {
-      if (model_->is_keyword_hint()) {
+      const bool shift_pressed = GetKeyState(VK_SHIFT) < 0;
+      if (model_->is_keyword_hint() && !shift_pressed) {
         // Accept the keyword.
         ScopedFreeze freeze(this, GetTextObjectModel());
         model_->AcceptKeyword();
-      } else if (!IsCaretAtEnd()) {
-        ScopedFreeze freeze(this, GetTextObjectModel());
-        OnBeforePossibleChange();
-        PlaceCaretAt(GetTextLength());
-        OnAfterPossibleChange();
+      } else if (shift_pressed &&
+                 model_->popup_model()->selected_line_state() ==
+                    AutocompletePopupModel::KEYWORD) {
+        model_->ClearKeyword(GetText());
       } else {
-        model_->CommitSuggestedText(true);
+        model_->OnUpOrDownKeyPressed(shift_pressed ? -count : count);
       }
       return true;
     }