Support painting panels with chromium themes on GTK.

chrome/browser/ui/panels/panel_browser_titlebar_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_PANELS_PANEL_BROWSER_TITLEBAR_GTK_H_
 #define CHROME_BROWSER_UI_PANELS_PANEL_BROWSER_TITLEBAR_GTK_H_
 
 #include "chrome/browser/ui/gtk/browser_titlebar.h"
+#include "ui/gfx/skia_util.h"
 
 class PanelBrowserWindowGtk;
 
 class PanelBrowserTitlebarGtk : public BrowserTitlebar {
  public:
   PanelBrowserTitlebarGtk(PanelBrowserWindowGtk* browser_window,
                           GtkWindow* window);
   virtual ~PanelBrowserTitlebarGtk();
 
   void UpdateMinimizeRestoreButtonVisibility();
 
+  // When a panel appears in the same position as the one of the panel being
+  // closed and the cursor stays in the close button, the close button appears
+  // not to be clickable. This is because neither "enter-notify-event" nor
+  // "clicked" event for the new panel gets fired if the mouse does not move.
+  // This creates a bad experience when a user has multiple panels of the same
+  // size (which is typical) and tries closing them all by repeatedly clicking
+  // in the same place on the screen.
+  //
+  // Opened a gtk bug for this -
+  //   https://bugzilla.gnome.org/show_bug.cgi?id=667841
+  void SendEnterNotifyToCloseButtonIfUnderMouse();
+
+  // Overridden from BrowserTitlebar:
+  virtual void UpdateButtonBackground(CustomDrawButton* button) OVERRIDE;
+  virtual void UpdateTitleAndIcon() OVERRIDE;
+  virtual void UpdateTextColor() OVERRIDE;
+
  protected:
   // Overridden from BrowserTitlebar:
   virtual bool BuildButton(const std::string& button_token,
                            bool left_side) OVERRIDE;
   virtual void GetButtonResources(const std::string& button_name,
                                   int* normal_image_id,
                                   int* pressed_image_id,
                                   int* hover_image_id,
                                   int* tooltip_id) const OVERRIDE;
   virtual int GetButtonOuterPadding() const OVERRIDE;
   virtual int GetButtonSpacing() const OVERRIDE;
   virtual void HandleButtonClick(GtkWidget* button) OVERRIDE;
   virtual void ShowFaviconMenu(GdkEventButton* event) OVERRIDE;
 
  private:
   friend class NativePanelTestingGtk;
 
   CustomDrawButton* unminimize_button() const {
     return unminimize_button_.get();
   }
 
+  SkColor GetTextColor() const;
+
   PanelBrowserWindowGtk* browser_window_;
 
   // All other buttons, including close and minimize buttons, are defined in
   // the base class BrowserTitlebar. This is indeed our restore button. But
   // we name it differently to avoid the confusion with restore_button defined
   // in the base class and used for unmaximize purpose.
   scoped_ptr<CustomDrawButton> unminimize_button_;
 
   DISALLOW_COPY_AND_ASSIGN(PanelBrowserTitlebarGtk);
 };
 
 #endif  // CHROME_BROWSER_UI_PANELS_PANEL_BROWSER_TITLEBAR_GTK_H_