[Search] No longer reverting omnibox text on instant search

chrome/browser/ui/omnibox/omnibox_edit_model.cc

 // Copyright 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/omnibox/omnibox_edit_model.h"
 
 #include <string>
 
 #include "base/auto_reset.h"
 #include "base/format_macros.h"
@@ skipping 611 matching lines @@
 
     // NOTE: Non-prepopulated engines will all have ID 0, which is fine as
     // the prepopulate IDs start at 1.  Distribution-specific engines will
     // all have IDs above the maximum, and will be automatically lumped
     // together in an "overflow" bucket in the histogram.
     UMA_HISTOGRAM_ENUMERATION("Omnibox.SearchEngine",
         template_url->prepopulate_id(),
         TemplateURLPrepopulateData::kMaxPrepopulatedEngineID);
   }
 
-  if (disposition != NEW_BACKGROUND_TAB) {
+  // Text in the omnibox needs to be reverted in the following cases:
+  // (1) Non-instant-extended query is committed (except to a background tab,
+  //     where the query stays in the omnibox e.g. middle-click).
+  // (2) Instant-extended query is committed on a new tab (foreground or
+  //     background). Current tab should show previous, reverted query.
+  bool is_instant_extended_search = controller()->GetInstant() &&
+      controller()->GetInstant()->IsInstantExtendedSearch();
+  if ((disposition != NEW_BACKGROUND_TAB && !is_instant_extended_search) ||
+      (is_instant_extended_search &&
+          (disposition == NEW_BACKGROUND_TAB ||
+           disposition == NEW_FOREGROUND_TAB))) {
     base::AutoReset<bool> tmp(&in_revert_, true);
     view_->RevertAll();  // Revert the box to its unedited state
   }
 
   if (match.type == AutocompleteMatch::EXTENSION_APP) {
     ExtensionAppProvider::LaunchAppFromOmnibox(match, profile_, disposition);
   } else {
     GURL destination_url(match.destination_url);
     // Append the query formulation time (time from when the user first typed a
     // character into the omnibox to when the user selected a query) to the AQS
@@ skipping 673 matching lines @@
     instant->OmniboxFocusChanged(state, reason, NULL);
 
   // Update state and notify view if the omnibox has focus and the caret
   // visibility changed.
   const bool was_caret_visible = is_caret_visible();
   focus_state_ = state;
   if (focus_state_ != OMNIBOX_FOCUS_NONE &&
       is_caret_visible() != was_caret_visible)
     view_->ApplyCaretVisibility();
 }