Handful of related instant changes:

chrome/browser/instant/instant_controller.h

 // Copyright (c) 2010 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_INSTANT_INSTANT_CONTROLLER_H_
 #define CHROME_BROWSER_INSTANT_INSTANT_CONTROLLER_H_
 #pragma once
 
 #include <set>
 
@@ skipping 22 matching lines @@
 //
 // At any time the TabContents maintained by InstantController may be destroyed
 // by way of |DestroyPreviewContents|, which results in |HideInstant| being
 // invoked on the delegate. Similarly the preview may be committed at any time
 // by invoking |CommitCurrentPreview|, which results in |CommitInstant|
 // being invoked on the delegate.
 class InstantController : public InstantLoaderDelegate {
  public:
   // Variations of instant support.
   enum Type {
+    // NOTE: these values are persisted to prefs. Don't change them!
+
     // Search results are shown for the best guess of what we think the user was
     // planning on typing.
-    PREDICTIVE_TYPE,
+    PREDICTIVE_TYPE = 0,
 
     // Search results are shown for exactly what was typed.
     VERBATIM_TYPE,
+
+    LAST_TYPE = VERBATIM_TYPE,
   };
 
   InstantController(Profile* profile, InstantDelegate* delegate);
   ~InstantController();
 
   // Registers instant related preferences.
   static void RegisterUserPrefs(PrefService* prefs);
 
+  // Records instant metrics.
+  static void RecordMetrics(Profile* profile);
+
   // Returns true if either type of instant is enabled.
   static bool IsEnabled(Profile* profile);
 
   // Returns true if the specified type of instant is enabled.
   static bool IsEnabled(Profile* profile, Type type);
 
+  // Enables instant.
+  static void Enable(Profile* profile);
+
+  // Disables instant.
+  static void Disable(Profile* profile);
+
   // Invoked as the user types in the omnibox with the url to navigate to.  If
   // the url is empty and there is a preview TabContents it is destroyed. If url
   // is non-empty and the preview TabContents has not been created it is
   // created.
   void Update(TabContents* tab_contents,
               const AutocompleteMatch& match,
               const string16& user_text,
               string16* suggested_text);
 
   // Sets the bounds of the omnibox (in screen coordinates). The bounds are
@@ skipping 134 matching lines @@
 
   // URL last pased to ScheduleUpdate.
   GURL scheduled_url_;
 
   const Type type_;
 
   DISALLOW_COPY_AND_ASSIGN(InstantController);
 };
 
 #endif  // CHROME_BROWSER_INSTANT_INSTANT_CONTROLLER_H_