Add onfocuschange to the Extended Search API, with associated isFocused attribute.

chrome/browser/ui/search/instant_controller.h

Index: chrome/browser/ui/search/instant_controller.h
diff --git a/chrome/browser/ui/search/instant_controller.h b/chrome/browser/ui/search/instant_controller.h
index fa4ab3a994ada823c52c4de25f389831b257e7b2..81b0a542fae4b66593422b642c97877fa4286dcf 100644
--- a/chrome/browser/ui/search/instant_controller.h
+++ b/chrome/browser/ui/search/instant_controller.h
@@ -503,6 +503,9 @@ class InstantController : public InstantPage::Delegate,
   // Omnibox focus state.
   OmniboxFocusState omnibox_focus_state_;
 
+  // The reason for the most recent omnibox focus change.
+  OmniboxFocusChangeReason omnibox_focus_change_reason_;
+
   // The search model mode for the active tab.
   SearchMode search_mode_;