Update Panel mininimize/restore button on strip and expansion state change.

chrome/browser/ui/panels/panel_browser_titlebar_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/panels/panel_browser_titlebar_gtk.h"
 
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/gtk/custom_button.h"
 #include "chrome/browser/ui/gtk/gtk_util.h"
@@ skipping 79 matching lines @@
   g_free(escaped_title);
   g_free(title_with_markup);
 }
 
 bool PanelBrowserTitlebarGtk::BuildButton(const std::string& button_token,
                                           bool left_side) {
   // Panel only shows close and minimize/restore buttons.
   if (button_token != "close" && button_token != "minimize")
     return false;
 
-  // Create unminimze button in order to show it to expand the minimized panel.
-  if (button_token == "minimize")
+  if (!BrowserTitlebar::BuildButton(button_token, left_side))
+    return false;
+
+  if (button_token == "minimize") {
+    // Create unminimze button, used to expand the minimized panel.
     unminimize_button_.reset(CreateTitlebarButton("unminimize", left_side));
 
-  return BrowserTitlebar::BuildButton(button_token, left_side);
+    // We control visibility of minimize and unminimize buttons.
+    gtk_widget_set_no_show_all(minimize_button()->widget(), TRUE);
+    gtk_widget_set_no_show_all(unminimize_button_->widget(), TRUE);
+  }
+  return true;
 }
 
 void PanelBrowserTitlebarGtk::GetButtonResources(const std::string& button_name,
                                                  int* normal_image_id,
                                                  int* pressed_image_id,
                                                  int* hover_image_id,
                                                  int* tooltip_id) const {
   if (button_name == "close") {
     *normal_image_id = IDR_PANEL_CLOSE;
     *pressed_image_id = 0;
@@ skipping 96 matching lines @@
   event->crossing.y_root = widget_allocation.y;
   event->crossing.mode = GDK_CROSSING_NORMAL;
   event->crossing.detail = GDK_NOTIFY_ANCESTOR;
   event->crossing.focus = true;
   event->crossing.state = 0;
 
   g_signal_emit_by_name(GTK_OBJECT(close_button()->widget()),
                         "enter-notify-event", event,
                         &return_value);
 }