Move TabStripModelDelegate off Browser into its own class.

chrome/browser/ui/gtk/tabs/tab_strip_gtk.cc

 // 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.
 
 #include "chrome/browser/ui/gtk/tabs/tab_strip_gtk.h"
 
 #include <gtk/gtk.h>
 
 #include <algorithm>
 #include <string>
@@ skipping 13 matching lines @@
 #include "chrome/browser/ui/browser_navigator.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/gtk/browser_window_gtk.h"
 #include "chrome/browser/ui/gtk/custom_button.h"
 #include "chrome/browser/ui/gtk/gtk_theme_service.h"
 #include "chrome/browser/ui/gtk/gtk_util.h"
 #include "chrome/browser/ui/gtk/tabs/dragged_tab_controller_gtk.h"
 #include "chrome/browser/ui/gtk/tabs/tab_strip_menu_controller.h"
 #include "chrome/browser/ui/tab_contents/tab_contents.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/browser/ui/tabs/tab_strip_model_delegate.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/browser/web_contents.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 #include "grit/theme_resources_standard.h"
 #include "grit/ui_resources.h"
 #include "ui/base/animation/animation_delegate.h"
 #include "ui/base/animation/slide_animation.h"
@@ skipping 2221 matching lines @@
 }
 
 void TabStripGtk::SetNewTabButtonBackground() {
   SkColor color = theme_service_->GetColor(
       ThemeService::COLOR_BUTTON_BACKGROUND);
   SkBitmap* background = theme_service_->GetBitmapNamed(
       IDR_THEME_WINDOW_CONTROL_BACKGROUND);
   SkBitmap* mask = theme_service_->GetBitmapNamed(IDR_NEWTAB_BUTTON_MASK);
   newtab_button_->SetBackground(color, background, mask);
 }