Implement {Start,Stop}CapturingKeyStrokes for Instant.

chrome/browser/ui/browser_instant_controller.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_BROWSER_INSTANT_CONTROLLER_H_
 #define CHROME_BROWSER_UI_BROWSER_INSTANT_CONTROLLER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/prefs/public/pref_change_registrar.h"
@@ skipping 45 matching lines @@
   void SetInstantSuggestion(const InstantSuggestion& suggestion);
 
   // Invoked by |instant_| to get the bounds that the preview is placed at,
   // in screen coordinated.
   gfx::Rect GetInstantBounds();
 
   // Invoked by |instant_| to notify that the preview gained focus, usually due
   // to the user clicking on it.
   void InstantPreviewFocused();
 
+  // Invoked by |instant_| to set invisible focus in the omnibox.
+  void SetInvisibleFocus();

[Peter Kasting, 2012/12/04 02:00:52]

Nit: Maybe this should be:

  // Invoked by |instant_| to give the omnibox focus invisibly.
  void FocusOmniboxInvisibly();

...since we're not really setting anything on the controller per se.

[samarth, 2012/12/04 04:55:35]

Done.

+
   // Invoked by |instant_| to get the currently active tab, over which the
   // preview would be shown.
   TabContents* GetActiveTabContents() const;
 
   // Invoked by |browser_| when the active tab changes.
   void ActiveTabChanged();
 
   // Invoked by |BrowserWindow| during layout to set content height which is
   // used as theme area height, i.e. the height of the area that the entire
   // theme background image should fill up.
@@ skipping 35 matching lines @@
   PrefChangeRegistrar profile_pref_registrar_;
 
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserInstantController);
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_UI_BROWSER_INSTANT_CONTROLLER_H_