Introduce a field trial for Instant.

chrome/browser/ui/webui/options/browser_options_handler.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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_OPTIONS_BROWSER_OPTIONS_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_OPTIONS_BROWSER_OPTIONS_HANDLER_H_
 #pragma once
 
 #include "chrome/browser/autocomplete/autocomplete_controller_delegate.h"
 #include "chrome/browser/prefs/pref_change_registrar.h"
@@ skipping 72 matching lines @@
   void DragDropStartupPage(const ListValue* args);
 
   // Gets autocomplete suggestions asychronously for the given string.
   // Called from WebUI.
   void RequestAutocompleteSuggestions(const ListValue* args);
 
   // Called when the 'Always show the bookmarks bar' checkbox is toggled.
   // Notifies any listeners interested in this event.  |args| is ignored.
   void ToggleShowBookmarksBar(const ListValue* args);
 
+  // Enables/disables instant.
+  void EnableInstant(const ListValue* args);
+  void DisableInstant(const ListValue* args);
+
+  // Called to request information about the Instant field trial.
+  void IsInstantFieldTrialExperimentGroup(const ListValue* args);
+
   // Returns the string ID for the given default browser state.
   int StatusStringIdForState(ShellIntegration::DefaultWebClientState state);
 
   // Gets the current default browser state, and asynchronously reports it to
   // the WebUI page.
   void UpdateDefaultBrowserState();
 
   // Updates the UI with the given state for the default browser.
   void SetDefaultBrowserUIString(int status_string_id);
 
@@ skipping 22 matching lines @@
   // CustomHomePagesTableModel, consider changing it to something more like
   // TemplateURLService.
   scoped_ptr<CustomHomePagesTableModel> startup_custom_pages_table_model_;
 
   scoped_ptr<AutocompleteController> autocomplete_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserOptionsHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_OPTIONS_BROWSER_OPTIONS_HANDLER_H_