Remove support for background masks. These are no longer necessary in the ne...

chrome/browser/gtk/back_forward_button_gtk.cc

Index: chrome/browser/gtk/back_forward_button_gtk.cc
===================================================================
--- chrome/browser/gtk/back_forward_button_gtk.cc	(revision 53847)
+++ chrome/browser/gtk/back_forward_button_gtk.cc	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -26,14 +26,13 @@
     : browser_(browser),
       is_forward_(is_forward),
       show_menu_factory_(this) {
-  int normal, pushed, hover, disabled, background, tooltip;
+  int normal, pushed, hover, disabled, tooltip;
   const char* stock;
   if (is_forward) {
     normal = IDR_FORWARD;
     pushed = IDR_FORWARD_P;
     hover = IDR_FORWARD_H;
     disabled = IDR_FORWARD_D;
-    background = IDR_FORWARD_MASK;
     tooltip = IDS_TOOLTIP_FORWARD;
     stock = GTK_STOCK_GO_FORWARD;
   } else {
@@ -41,14 +40,12 @@
     pushed = IDR_BACK_P;
     hover = IDR_BACK_H;
     disabled = IDR_BACK_D;
-    background = IDR_BACK_MASK;
     tooltip = IDS_TOOLTIP_BACK;
     stock = GTK_STOCK_GO_BACK;
   }
   button_.reset(new CustomDrawButton(
       GtkThemeProvider::GetFrom(browser_->profile()),
-      normal, pushed, hover, disabled, background, stock,
-      GTK_ICON_SIZE_SMALL_TOOLBAR));
+      normal, pushed, hover, disabled, stock, GTK_ICON_SIZE_SMALL_TOOLBAR));
   gtk_widget_set_tooltip_text(widget(),
                               l10n_util::GetStringUTF8(tooltip).c_str());
   menu_model_.reset(new BackForwardMenuModel(browser, is_forward ?