Implementation for switching between recently used tabs using ctrl tilde or quoteleft.

chrome/browser/ui/gtk/browser_window_gtk.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.
 
 #ifndef CHROME_BROWSER_UI_GTK_BROWSER_WINDOW_GTK_H_
 #define CHROME_BROWSER_UI_GTK_BROWSER_WINDOW_GTK_H_
 #pragma once
 
 #include <gtk/gtk.h>
 
@@ skipping 412 matching lines @@
   // of the matched accelerator.
   static gboolean OnGtkAccelerator(GtkAccelGroup* accel_group,
                                    GObject* acceleratable,
                                    guint keyval,
                                    GdkModifierType modifier,
                                    void* user_data);
 
   // Key press event callback.
   CHROMEGTK_CALLBACK_1(BrowserWindowGtk, gboolean, OnKeyPress, GdkEventKey*);
 
+  // Key release event callback.
+  CHROMEGTK_CALLBACK_1(BrowserWindowGtk, gboolean, OnKeyRelease, GdkEventKey*);
+
   // Mouse move and mouse button press callbacks.
   CHROMEGTK_CALLBACK_1(BrowserWindowGtk, gboolean, OnMouseMoveEvent,
                        GdkEventMotion*);
   CHROMEGTK_CALLBACK_1(BrowserWindowGtk, gboolean, OnButtonPressEvent,
                        GdkEventButton*);
 
   // Tracks focus state of browser.
   CHROMEGTK_CALLBACK_1(BrowserWindowGtk, gboolean, OnFocusIn,
                        GdkEventFocus*);
   CHROMEGTK_CALLBACK_1(BrowserWindowGtk, gboolean, OnFocusOut,
@@ skipping 124 matching lines @@
   scoped_ptr<FullscreenExitBubbleGtk> fullscreen_exit_bubble_;
 
   FullscreenExitBubbleType fullscreen_exit_bubble_type_;
 
   content::NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserWindowGtk);
 };
 
 #endif  // CHROME_BROWSER_UI_GTK_BROWSER_WINDOW_GTK_H_