An edit for SetText needs to be merged with previous edit for omnibox.

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

Index: chrome/browser/ui/views/omnibox/omnibox_view_views.cc
diff --git a/chrome/browser/ui/views/omnibox/omnibox_view_views.cc b/chrome/browser/ui/views/omnibox/omnibox_view_views.cc
index ad04876f65e3be351d3333fe739628d41328cf9d..db2390c5744edc8c7e3cc7df19c65757a66a0646 100644
--- a/chrome/browser/ui/views/omnibox/omnibox_view_views.cc
+++ b/chrome/browser/ui/views/omnibox/omnibox_view_views.cc
@@ -322,6 +322,7 @@ void OmniboxViewViews::Update(const TabContents* contents) {
       // Move the marks for the cursor and the other end of the selection to
       // the previously-saved offsets (but preserve PRIMARY).
       textfield_->SelectRange(state->view_state.selection_range);
+      textfield_->ClearEditHistory();

[msw, 2011/06/02 10:16:42]

perhaps comment on why we're doing this. (I'm not sure, myself)

[oshima, 2011/06/02 19:11:42]

Done. Added TODO for future improvement.

     }
   } else if (visibly_changed_permanent_text) {
     RevertAll();