Implement {Start,Stop}CapturingKeyStrokes for Instant.

chrome/browser/ui/search/search_types.h

Index: chrome/browser/ui/search/search_types.h
diff --git a/chrome/browser/ui/search/search_types.h b/chrome/browser/ui/search/search_types.h
index b4804c161196a30e49a3685d72e6c56cd8ef7a15..8aa2dec2ab628301655c7b9d135c7810bdd40bf4 100644
--- a/chrome/browser/ui/search/search_types.h
+++ b/chrome/browser/ui/search/search_types.h
@@ -49,6 +49,9 @@ struct Mode {
     // On the NTP page and the NTP is ready to be displayed.
     MODE_NTP,
 
+    // On the NTP page and the web searchbox has focus.
+    MODE_NTP_WEB_SEARCHBOX_HAS_FOCUS,

[dhollowa, 2012/11/15 21:31:00]

I'm not so crazy about mixing this in with the Mode.  Seems like to model should
have a boolean for focus state.

+
     // On the NTP page and the Omnibox is modified in some way.
     MODE_SEARCH_SUGGESTIONS,
 
@@ -72,7 +75,7 @@ struct Mode {
   }
 
   bool is_ntp() const {
-    return mode == MODE_NTP;
+    return mode == MODE_NTP || mode == MODE_NTP_WEB_SEARCHBOX_HAS_FOCUS;
   }
 
   bool is_search() const {