Local omnibox treats navsuggest suggestions as queries.

chrome/browser/ui/search/instant_controller.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/search/instant_controller.h"
 
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
@@ skipping 554 matching lines @@
       DVLOG(1) << "Waiting for " << (*provider)->GetName();
       return;
     }
     for (ACMatches::const_iterator match = (*provider)->matches().begin();
          match != (*provider)->matches().end(); ++match) {
       InstantAutocompleteResult result;
       result.provider = UTF8ToUTF16((*provider)->GetName());
       result.type = UTF8ToUTF16(AutocompleteMatch::TypeToString(match->type));
       result.description = match->description;
       result.destination_url = UTF8ToUTF16(match->destination_url.spec());
-      if (from_search_provider)
+
+      // If the search query should be displayed.

[samarth, 2013/04/17 00:39:13]

nit: this comment isn't very useful.  How about something like "Setting the
search_query field tells the Instant page to treat the suggestion as a query." 
Or you could just leave this out altogether.

Ideally we'd test this function directly by passing in a list of matches and
checking the "output", but that's not really feasible today.

[dougw, 2013/04/19 01:11:09]

Done.

+      if (AutocompleteMatch::IsSearchType(match->type))
         result.search_query = match->contents;
+
       result.transition = match->transition;
       result.relevance = match->relevance;
       DVLOG(1) << "    " << result.relevance << " " << result.type << " "
                << result.provider << " " << result.destination_url << " '"
                << result.description << "' '" << result.search_query << "' "
                << result.transition;
       results.push_back(result);
     }
   }
   LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
@@ skipping 1044 matching lines @@
     return false;
 
   // If this is not window startup, switch.
   // TODO(shishir): This is not completely reliable. Find a better way to detect
   // startup time.
   if (browser_->GetActiveWebContents())
     return true;
 
   return chrome::IsAggressiveLocalNTPFallbackEnabled();
 }