Add support for providers called when the omnibox is focused.

chrome/browser/autocomplete/zero_suggest_provider.cc

Index: chrome/browser/autocomplete/zero_suggest_provider.cc
diff --git a/chrome/browser/autocomplete/zero_suggest_provider.cc b/chrome/browser/autocomplete/zero_suggest_provider.cc
index efa39c39f3cf2d5e3ffd0b7adb858364802beb74..7a4454bc69f3a581ef5f49e5ae31e7cd58376349 100644
--- a/chrome/browser/autocomplete/zero_suggest_provider.cc
+++ b/chrome/browser/autocomplete/zero_suggest_provider.cc
@@ -153,7 +153,7 @@ void ZeroSuggestProvider::Stop(bool clear_cached_results) {
   if (clear_cached_results) {
     // We do not call Clear() on |results_| to retain |verbatim_relevance|
     // value in the |results_| object. |verbatim_relevance| is used at the
-    // beginning of the next StartZeroSuggest() call to determine the current
+    // beginning of the next StartOnOmniboxFocus() call to determine the current
     // url match relevance.
     results_.suggest_results.clear();
     results_.navigation_results.clear();
@@ -177,6 +177,10 @@ void ZeroSuggestProvider::AddProviderInfo(ProvidersInfo* provider_info) const {
     provider_info->back().set_times_returned_results_in_session(1);
 }
 
+bool ZeroSuggestProvider::ActivatedOnOmniboxFocus() const {
+  return true;
+}
+
 void ZeroSuggestProvider::ResetSession() {
   // The user has started editing in the omnibox, so leave
   // |field_trial_triggered_in_session_| unchanged and set