Add a URL param to indicate group selection in Instant field trial.

chrome/browser/autocomplete/keyword_provider.h

 // Copyright (c) 2011 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.
 //
 // This file contains the keyword autocomplete provider. The keyword provider
 // is responsible for remembering/suggesting user "search keyword queries"
 // (e.g.  "imdb Godzilla") and then fixing them up into valid URLs.  An
 // instance of it gets created and managed by the autocomplete controller.
 // KeywordProvider uses a TemplateURLService to find the set of keywords.
 //
@@ skipping 86 matching lines @@
   // the first intervening whitespace).
   // If |trim_leading_whitespace| is true then leading whitespace in
   // |*remaining_input| will be trimmed.
   static string16 SplitKeywordFromInput(const string16& input,
                                         bool trim_leading_whitespace,
                                         string16* remaining_input);
 
   // Fills in the "destination_url" and "contents" fields of |match| with the
   // provided user input and keyword data.
   static void FillInURLAndContents(
+      Profile* profile,
       const string16& remaining_input,
       const TemplateURL* element,
       AutocompleteMatch* match);
 
   // Determines the relevance for some input, given its type, whether the user
   // typed the complete keyword, and whether the user is in "prefer keyword
   // matches" mode, and whether the keyword supports replacement.
   // If |allow_exact_keyword_match| is false, the relevance for complete
   // keywords that support replacements is degraded.
   static int CalculateRelevance(AutocompleteInput::Type type,
@@ skipping 40 matching lines @@
   // If non-empty, holds the ID of the extension whose keyword is currently in
   // the URL bar while the autocomplete popup is open.
   std::string current_keyword_extension_id_;
 
   NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(KeywordProvider);
 };
 
 #endif  // CHROME_BROWSER_AUTOCOMPLETE_KEYWORD_PROVIDER_H_