Implement {Start,Stop}CapturingKeyStrokes for Instant.

chrome/browser/ui/omnibox/omnibox_view.h

 // Copyright (c) 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.
 
 // This file defines the interface class OmniboxView.  Each toolkit will
 // implement the edit view differently, so that code is inherently platform
 // specific.  However, the OmniboxEditModel needs to do some communication with
 // the view.  Since the model is shared between platforms, we need to define an
 // interface that all view implementations will share.
 
@@ skipping 134 matching lines @@
   virtual void UpdatePopup() = 0;
 
   // Closes the autocomplete popup, if it's open. The name |ClosePopup|
   // conflicts with the OSX class override as that has a base class that also
   // defines a method with that name.
   virtual void CloseOmniboxPopup();
 
   // Sets the focus to the autocomplete view.
   virtual void SetFocus() = 0;
 
+  // Sets the focus to the autocomplete view but doesn't visibly show focus to
+  // the user (i.e. no blinking caret or border highlight).

[Mathieu, 2012/11/28 17:56:10]

nit: On Aura, Windows and Gtk, I have not seen border highlight. I would leave
this out.

[samarth, 2012/11/28 19:42:43]

The highlight only exists on Mac afaik. I'll take this out.

+  virtual void SetInvisibleFocus() = 0;
+
   // Called when the temporary text in the model may have changed.
   // |display_text| is the new text to show; |save_original_selection| is true
   // when there wasn't previously a temporary text and thus we need to save off
   // the user's existing selection.
   virtual void OnTemporaryTextMaybeChanged(const string16& display_text,
                                            bool save_original_selection) = 0;
 
   // Called when the inline autocomplete text in the model may have changed.
   // |display_text| is the new text to show; |user_text_length| is the length of
   // the user input portion of that (so, up to but not including the inline
@@ skipping 86 matching lines @@
   scoped_ptr<OmniboxEditModel> model_;
   OmniboxEditController* controller_;
   ToolbarModel* toolbar_model_;
 
   // The object that handles additional command functionality exposed on the
   // edit, such as invoking the keyword editor.
   CommandUpdater* command_updater_;
 };
 
 #endif  // CHROME_BROWSER_UI_OMNIBOX_OMNIBOX_VIEW_H_