Implement tooltips for the Go/Stop button in Linux.

chrome/browser/gtk/go_button_gtk.h

 // Copyright (c) 2009 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_GTK_GO_BUTTON_GTK_H_
 #define CHROME_BROWSER_GTK_GO_BUTTON_GTK_H_
 
 #include <gtk/gtk.h>
 
 #include "base/basictypes.h"
 #include "base/task.h"
 #include "chrome/browser/gtk/custom_button.h"
 #include "chrome/common/owned_widget_gtk.h"
 
 class Browser;
+class LocationBarViewGtk;
 class Task;
 
 class GoButtonGtk {
  public:
   enum Mode { MODE_GO = 0, MODE_STOP };
   enum ButtonState { BS_NORMAL = 0, BS_HOT };
 
-  explicit GoButtonGtk(Browser* browser);
+  GoButtonGtk(LocationBarViewGtk* location_bar, Browser* browser);
   ~GoButtonGtk();
 
   GtkWidget* widget() const { return widget_.get(); }
   ButtonState state() const { return state_; }
 
   // Force the button state.  Useful for when the foreground tab changes.
   void ChangeMode(Mode mode);
 
   // Ask for a specified button state.  This is called when the loading state of
   // the tab changes.  This method may postpone the actual ChangeMode() call
   // until another event (such as waiting for a potential double click to end,
   // or for the mouse to stop hovering over the button).
   void ScheduleChangeMode(Mode mode);
 
  private:
   friend class GoButtonGtkPeer;
 
   // gtk signals
   static gboolean OnExpose(GtkWidget* widget,
                            GdkEventExpose* e,
                            GoButtonGtk* button);
   static gboolean OnEnter(GtkButton* widget, GoButtonGtk* button);
   static gboolean OnLeave(GtkButton* widget, GoButtonGtk* button);
   static gboolean OnClicked(GtkButton* widget, GoButtonGtk* button);
 
+  void SetToggled();
+
   Task* CreateButtonTimerTask();
   void OnButtonTimer();
+  void SetTooltip();
+
+  LocationBarViewGtk* const location_bar_;
 
   // Keep a pointer to the Browser object to execute commands on it.
   Browser* const browser_;
 
   // Delay time to wait before allowing a mode change.  This is to prevent a
   // mode switch while the user is double clicking.
   int button_delay_;
   ScopedRunnableMethodFactory<GoButtonGtk> stop_timer_;
 
   // The mode we should be in
   Mode intended_mode_;
 
   // The currently-visible mode - this may different from the intended mode
   Mode visible_mode_;
 
   ButtonState state_;
 
   CustomDrawButtonBase go_;
   CustomDrawButtonBase stop_;
 
   OwnedWidgetGtk widget_;
 
   DISALLOW_COPY_AND_ASSIGN(GoButtonGtk);
 };
 
 #endif  // CHROME_BROWSER_GTK_GO_BUTTON_GTK_H_