A working implementation of AQS (Assisted Query Stats).

chrome/browser/autocomplete/autocomplete.h

Index: chrome/browser/autocomplete/autocomplete.h
diff --git a/chrome/browser/autocomplete/autocomplete.h b/chrome/browser/autocomplete/autocomplete.h
index d928e0a3875aa8f4fdbdbcae7db8ab9757225351..395be10f873fc65305553dc8992a3f8a58664ba2 100644
--- a/chrome/browser/autocomplete/autocomplete.h
+++ b/chrome/browser/autocomplete/autocomplete.h
@@ -562,6 +562,7 @@ class AutocompleteResult {
 
   // Returns the match at the given index.
   const AutocompleteMatch& match_at(size_t index) const;
+  AutocompleteMatch* match_at(size_t index);
 
   // Get the default match for the query (not necessarily the first).  Returns
   // end() if there is no default match.
@@ -732,6 +733,7 @@ class AutocompleteController : public ACProviderListener {
   friend class AutocompleteProviderTest;
   FRIEND_TEST_ALL_PREFIXES(AutocompleteProviderTest,
                            RedundantKeywordsIgnoredInResult);
+  FRIEND_TEST_ALL_PREFIXES(AutocompleteProviderTest, UpdateAssistedQueryStats);
 
   // Updates |result_| to reflect the current provider state.  Resets timers and
   // fires notifications as necessary.  |is_synchronous_pass| is true only when
@@ -747,6 +749,11 @@ class AutocompleteController : public ACProviderListener {
   // provider name as a description on the first match in the group.
   void UpdateKeywordDescriptions(AutocompleteResult* result);
 
+  // For each AutocompleteMatch returned by SearchProvider, updates the
+  // destination_url iff the provider's TemplateURL supports assisted query
+  // stats.
+  void UpdateAssistedQueryStats(AutocompleteResult* result);
+
   // Calls AutocompleteControllerDelegate::OnResultChanged() and if done sends
   // AUTOCOMPLETE_CONTROLLER_RESULT_READY.
   void NotifyChanged(bool notify_default_match);